Ancient History & Civilisation

Chapter Two

Gathering Troops in the War God's Field

If you were on the Capitoline facing north on a summer's day in 717 B.C.E., you would have witnessed, according to Plutarch, a large thundercloud drifting ever lower until it touched the swampy ground in the general area where the Pantheon now stands. That ominous mist was about to envelop and carry off Rome's sacred and mythical founder, Romulus.1 Livy described the fantastical scene occurring on the Nones of Quintilis (July 7), noting that,

as the king was holding a muster in the Campus Martius, near the swamp of Capra [or Goat Marsh], for the purpose of reviewing the army, suddenly a storm came up, with loud claps of thunder, and enveloped him in a cloud so thick as to hide him from the sight of the assembly; and from that moment Romulus was no more on earth.2

On seeing Romulus's throne empty, the citizens unanimously recognized that their king had transformed into a deity; they quickly declared Romulus to be a god and the son of a god.3 This story is revealing in several respects: it suggests a popular recollection of the Campus Martius as a place to muster troops; it notes the early topography of the area as marshy; and, by describing Romulus's ascension, it creates the conditions for a sacred space. As discussed later in this chapter, many centuries after this mythical event, Romans were still making an annual pilgrimage to the Caprae Palus on a holiday called the Nonae Capratinae (Nones of the Goat), possibly to celebrate Romulus's apotheosis.4

Mustering for Battle

To contemporaries of Livy or Plutarch, there were few, if any, visual cues afforded by the field, then covered by temples, baths, and colonnades, to indicate to them that large numbers of soldiers would have once massed there and witnessed an apotheosis or, indeed, gathered together for any other purpose. Yet the memory of the Campus Martius as a mustering ground persisted, as evidenced by two stories Livy recounted. In 458 B.C.E., the Roman people urged Cincinnatus to come to the aid of the city and lift the siege laid by the Aequians against the camp of the hapless consul L. Minucius Esquilinus. Cincinnatus, then out plowing his fields, was convinced to drop his tools, don his toga, and assume emergency dictatorial powers. Before dawn the following day, he met the assembled citizens in the Forum and issued instructions that before sunset each man of military age was to assemble in the Campus Martius with his equipment and supplies. Cincinnatus's command was heeded. By sunset the battle-ready troops were assembled on the Field of Mars. The army promptly marched from there to the battlefield and, in short order, defeated the Aequians.5 Similarly, Livy recorded how, in preparation for battle against the Volscians in 446 B.C.E., “the standards were fetched from the treasury by the quaestors that very day, and being carried to the Campus Martius, headed the line of march from the mustering ground.”6

From the city's earliest days, the flat plain north of the city walls provided an ideal location for the gathering of troops. First and foremost, it was outside the pomerium and, therefore, the plain was a permissible collection point for Rome's army.7 Second, at 1.7 square kilometers in size, the area between the river and the later-built Via Flaminia provided more than enough space for assembling many citizens, whether for military or enumeration purposes. Third, the military provided protection to those gathering to vote, and because the Campus Martius was used for that purpose, the army's presence amid the election activities was appropriate.8 Fourth, after the completion of the Via Flaminia in the late third century B.C.E., soldiers who gathered in the Campus Martius could mobilize quickly to engage Rome's enemies located north of the capital.

While the field was well established by the fifth century B.C.E. as a mustering ground for the city's army, it was not the only location for assembling troops outside the pomerium. Livy's account of preparation for battle against the Gauls in Latium in 350 B.C.E.notes that, rather than assemble in the Campus Martius, all young men were ordered to appear by the Temple of Mars located along the Via Appia, south of the city.9 Because the Gauls were camped along the Alban Mount by which the Appian Way passed, it is reasonable that armies heading southeast from Rome would gather outside the pomerium on the southern side of the city rather than circumnavigate the perimeter of the walls from the Campus Martius. However, because the army was assembled in the Field of Mars for reasons other than just receiving its marching orders, there may have been a combination of various martial activities that made the space the primary military gathering location.

For instance, the campus was the site of the census that took place every five years for the purpose of dividing the male citizenry into appropriate military units.10 Rome's legendary sixth-century B.C.E. king, Servius Tullius, was credited with holding the first census to organize the army into wealth-based military units known as centuries. Livy recounts that once the initial census was completed, Servius issued a proclamation commanding all Roman citizens, “to assemble at daybreak, each in his own century, in the Campus Martius.”11 Once assembled, enrolled citizens witnessed a lustrum, a blood offering to the god Mars, signaling the completion of the census and intended for purification. Magistrates sacrificed a pig, a sheep, and a bull in an exceptionally sacred ceremony known as the suovetaurilia.12 A famous marble relief in the Louvre, reportedly found in the area of the Circus Flaminius, depicts a lustration with the three sacrificial animals (Figure 3).13 In 443 B.C.E., officials called censors were first used to conduct the census.Eight years later, the Villa Publica was established to provide a fixed location on the Campus Martius at which citizens could gather and be counted.14 Centuriate assemblies, or comitia centuriata, also met on the plain to choose their commanders and vote for war or peace.15 Cassius Dio recorded that all soldiers were required to attend the assemblies.16 As John Rich has written, it was “no accident that, when the people met to elect their chief magistrates, who commanded the army, they assembled outside the city on the Campus Martius – the field of Mars, the war god.”17

3. Detail, suovetaurilia from the Paris/Munich reliefs (formerly known as the Altar of Ahenobarbus) (first century B.C.E.). Louvre, Paris. (Photo: © RMN-Grand Palais / Art Resource, New York)

Although Livy claims that Servius Tullius enrolled 80,000 citizens in the first military census, the army in the field was much smaller.18 It originally consisted of at least one legion (from legio, meaning “to levy”) of sixty centuries, each composed of approximately 100 infantry soldiers for a total of 6,000 heavily armed infantry plus 2,400 velites, soldiers with light weaponry.19 For much of the republic, the size of a century fluctuated, but in Polybius's day a legion was composed generally of 4,200 soldiers and 5,000 in times of special danger.20 By the end of the fourth century B.C.E., the army contained four legions or approximately 16,000 men,21 a size that could be easily organized in the open field north of the pomerium.

The requirement that the military gather outside of the pomerium was a centuries-old tradition; however, there were no obvious physical boundary markers for the pomerium other than stone cippi until the so-called Servian Wall was built in the fourth centuryB.C.E. (See Plan 5.)22 Although Livy credits the sixth-century B.C.E. king with constructing the wall and thereby extending the pomerium to the approximate limits of the enclosure,23 it is widely accepted that the eponymous reference to Servius Tullius is incorrect and that the wall postdated the sack of the city by the Gauls in 390 B.C.E.24 Approximately eleven kilometers in length, the fortification enclosed just under five square kilometers of the city, or two and one-third times the area of the Campus Martius, encircling all or part of the original seven hills of Rome.25 The pomerial line delineated the ritually defined boundary, but it was the stone ramparts themselves that provided the physical barrier preventing uniformed soldiers from entering the city without senatorial permission. When viewed in conjunction with the Villa Publica established a half century earlier, the Servian Wall must have clearly delimited the Campus Martius as a space important to Rome's strong and developing military traditions.

Even though it was considered most prudent to keep armed soldiers outside of the city walls, it was risky, because it made other areas of Rome vulnerable to attack when its forces were mostly concentrated on the northern plain. Although the Tiber River and the nearby foothills of the Apennines might have provided some sense of security from northern invaders, this was not actually the case. As the Gallic sack of Rome in 390 B.C.E. demonstrated, the northern plain was easily bypassed by attackers who simply laid siege to the city from other, more vulnerable points.26 To prevent sneak attacks, sentries flew a red flag from the Janiculum Hill to signal that no enemy was in sight.27

Beginning in the mid-fifth century B.C.E., a pattern of annual warfare began to develop. Rome was at war for fifteen of the twenty-five years from 440 to 416 B.C.E., and thereafter, during the century and a half from 415 B.C.E. to the beginning of the First Punic Warin 264 B.C.E., there were only thirteen years when Rome was not fighting its enemies.28 During the fifth century, the battles were conducted in alliance with other tribes and with a limited geographic reach as Rome fought the Volsci, the Aequi, and the southern Etruscans.29 As one author has noted, Rome was a “frontier-town,” with the Tiber that ran the length of the Campus Martius and beyond serving as the border with territory controlled by Etruria.30 By the fourth century B.C.E., however, the Romans were battling in the Samnite Wars for supremacy of the Italian Peninsula and, thus, fighting further and further from their home base. Nevertheless, with exceptions such as the lengthy siege of Veii resulting in its capture in 396 B.C.E., until the start of the First Punic War in 264B.C.E., Roman warfare generally had what has been called an “annual rhythm,” with most campaigns restricted to the summer months.31 The Campus Martius would have been part of this seasonal cycle, witnessing the collection of troops in the spring and their discharge every fall.

The three Punic Wars and several military confrontations with the Greek kings in the eastern Mediterranean far from Rome brought significant changes to the yearly military musters and to the use, therefore, of the Campus Martius. As many as ten legions were deployed to fight Rome's distant enemies and, as a result, permanent, manned garrisons were created.32 By the beginning of the Second Punic War in 218 B.C.E., service in the military had generally changed from part-time, seasonal campaigns to year-round duty,33 although at that time the soldiers made up what has been termed a “peoples’ army,” with as much as 26 percent of the male population participating in the war.34 An elected magistrate returning to Rome in the fall brought with him only those soldiers who had finished their years of service. In the spring, his successor would head out to meet his troops with new recruits in tow.35

Some historians believe that since campaigns were often conducted far from Rome in the third century B.C.E., the procedure for declaring war was altered, too, and it seems likely that the martial functions of the Campus Martius may have changed. Livywrote that during the time of the kings, Roman priests, known as fetiales, would ceremonially cast a spear into enemy territory prior to the formal declaration of war in Rome.36 The priest would travel to the disputed territory and demand redress for a perceived wrong. Then, according to Livy, if after thirty-three days his requests failed to accomplish the desired result, the fetialis returned to Rome for consultation. After approval from the Senate, the priest would once again depart for the enemy lines, tossing a spear across the border to signal the official commencement of war. Although Livy claimed that the practice was continued by later generations, the several examples of fetiales going to the enemy to declare war in the fourth and early third centuries B.C.E. make no mention of the spear-hurling ceremony.37 Late Roman commentators explained that the practice became impractical when enemies were pushed further and further from the city limits and that as a result the ritual was revised around 280 B.C.E. with senatorial legates throwing a spear into specially designated “enemy territory” located in the area later known as the Circus Flaminius.38 In an act of war declaration against Mark Antony and Cleopatra, Augustus hurled a spear from a location near a war column, or columna bellica, in the area of the Temple of Bellona, the war goddess.39 Whether the use of the southern end of the Campus Martius as mock enemy territory was simply a bit of drama started by Augustus or was begun more than two centuries earlier, the fact that the space was outside of thepomerium would have made it appropriate for that purpose.40

As the theaters of war spread beyond the Italian Peninsula in the third century B.C.E., Rome needed to move its troops farther and faster. Likely in anticipation of renewed fighting with the Carthaginians, the Via Flaminia was constructed in 220 B.C.E. to cut roughly north-south through the plain along a previous path. Once completed, the road would come to demarcate clearly the eastern edge of the Campus Martius.41 When the censor Gaius Flaminius Nepos finished the highway, it stretched approximately 362 kilometers from the Porta Fontinalis in the Servian Wall by the Capitoline to the Milvian Bridge and then north to Ariminum, ancient Rimini.42 The new road facilitated the quick march of troops north through the Italian Peninsula and ultimately to Spain, a strategically important territory during the Second Punic War.43

When the Third Punic War ended in 146 B.C.E., the whole of the Mediterranean basin was under Roman control.44 Rome's soldiers, now scattered far and wide, no longer marched home at the end of a season of battles. By the early first century B.C.E., the annual levies of citizens for war appear to have stopped, and with the military reforms under the consulship of Gaius Marius in 104 B.C.E., landless citizens, the so-called capite censi, were accepted into an army now better organized into units called cohorts.45During the reign of Augustus the citizen army finally disappeared, replaced by professional soldiers serving for as long as twenty-five years.46 In the first century B.C.E., the function of the Field of Mars as a gathering point for the deployment of soldiers abroad must have greatly diminished, although its use for musters had not stopped altogether. In 82 B.C.E., Sulla rushed his army back to Rome to oppose the forces of Marius inside the city. He had his army camp before the northern gates in the campus to await his orders.47Years later when Octavian advanced on the forces of Crassus that were held up in the capital city, he ordered his troops to establish a stronghold in the Campus Martius.48 In these instances of civil war, the field was useful as a staging area for troops to engage in military intimidation of those within the walls rather than as a gathering point from which to march out to challenge foreign enemies.

Although construction projects in the plain began to encroach on the areas available for military exercises during the first century B.C.E., nonetheless sufficient space remained for that purpose if required, both within enclosed spaces and in open fields. The Villa Publica was large enough to house approximately 4,000 prisoners of war during the early part of the century.49 The Saepta voting precinct could accommodate perhaps as many as 70,000 people at one time.50 It is important to note that most of the northern part of the plain remained completely undeveloped until the building program of Augustus. Although musters for battle preparation were now rare, the open space in the Campus Martius continued to be used during the first century B.C.E. as a military exercise area and parade ground.51 Writing a paean to peace during the first half of the first century B.C.E., the poet Lucretius despaired of “legions swarming round the Field of Mars [campi], rousing a mimic warfare – either side strengthened with large auxiliaries and horse, alike equipped with arms, alike inspired.”52 Varro described walking among the shade trees of the Villa Publica where “the cohorts encamp for a consular review, and here they display their arms.”53 In his youth, the future emperor Augustus would practice riding and other military exercises in the Campus Martius.54 The imperative for a wide-open space had diminished, but at least until the late republic it was available for large military gatherings.

Rome's navy also utilized the Field of Mars. Archaeological evidence for the Roman naval arsenal and shipyards (navalia) along the Tiber's edge has been excavated upstream of the modern Ponte Sant’Angelo and tentatively dated to the fourth centuryB.C.E.55The navalia consisted of covered docks with peaked roofs over each ship.56 After a naval battle in 338 B.C.E., ships of the Latin tribes that were not destroyed were brought back to the navalia,57 and the naval forces of the consul Lutatius Catulus likely launched from the navalia in 242 B.C.E. during the First Punic War, ultimately returning home in triumph.58 As with the army, the navy's use of the campus as a gathering point decreased with the onset of the imperial era. In the case of sailors, however, the reason had more to do with navigational limitations than changes in conscription. Silt began to obstruct the Tiber's mouth, prompting larger boats to be maintained at Puteoli in the south and at the nearby port at Ostia. The ship sheds, though, were not abandoned. Pliny notes that they were employed to house animals destined for games in the Circus Maximus, a use that also fit well with the changes in the function of the Field of Mars during the imperial period to a center of entertainment and recreation.59

The topographical characteristics of the Campus Martius that made it appropriate for collecting soldiers, whether for battle or political purposes, also presented certain limitations. As discussed in more detail in Chapter 6, the low, flat plain was prone to flooding in the late fall to early spring and generally marshy, particularly in the central area where the Pantheon now stands. Summer months saw swarms of mosquitoes and the risk in early fall of malaria. The seasonal nature of warfare during the early and mid-republic correlated with the topographical challenges presented by the low ground of the plain. Following the selection of new consuls each year, soldiers were collected every spring after the end of the winter rains to go off to do battle and returned in the fall after the dangers from mosquitoes abated but before the rains of late fall.60

Whatever difficulties a swampy plain presented to gathering an army at certain times of the year, the nearby hills overlooking the Campus Martius provided excellent vantage points from which officers and magistrates might observe military formations down below. Rome's army remained outside the pomerium, in large part because armed soldiers were not to be fully trusted, and just as the magistrates might watch the red flag of warning on the Janiculum, so too, the soldiers’ actions could have been viewed from a hilltop.

Rome's armies also participated in the city's public pageantry and, in that sense, the Field of Mars was a stage for citizens to observe martial preparedness and entertainment. For instance, Livy noted that having defeated the Volscians and killed more than 13,000 of their men in 461 B.C.E., the Roman army under the leadership of the consul Lucretius laid out all of the captured booty in the plain for three days for public inspection and for reclamation by anyone recognizing his property.61 When the last of the Macedonian line of Alexander the Great, Perseus of Macedon, was defeated in the Third Macedonian War, his flagship was brought to Rome. The city's population lined the Tiber's banks as the massive ship with sixteen banks of oars came up river to its berth at thenavalia, laden with “splendid armor [and] royal fabrics.”62 In a separate event, Plutarch reported how the aged and somewhat corpulent general and consul Marius would draw a crowd by donning his armor and going to the campus to engage in equestrian gameswith much younger men.63 Moreover, Octavian's spear toss into the symbolic “foreign” territory by the Temple of Bellona most certainly attracted an interested audience.

Whether viewed from the hilltops or up close, the military activity on the Campus Martius that likely transfixed most observers was the triumph. When significant battlefield success had been achieved, a conquering general and his victorious men could be awarded a military parade that would assemble with arms in the field and, in this rare instance, cross the pomerial line into the city. The triumphal procession helped accentuate the significance of the plain north of the pomerium as a center of activities associated with warfare in contradistinction to the city as a refuge of peace. A general who crossed the pomerium without having been awarded a triumph by the Senate lost his right to obtain that honor.64 Fragmentary inscriptions carved at the time of Augustus, the Fasti Triumphales, record more than 200 military triumphs reaching back to Rome's mythical founding in the eighth century B.C.E.65

Because the Field of Mars was used for centuries as an important location to collect and send troops off to battle and to celebrate their return, it is not surprising that the space reflected myth and legend. However, by the time Livy recounted the story of how Romulus, a son of Mars, rose to heaven while surrounded by his mustered troops, soldiers had stopped using the campus for war preparations. Similarly, triumphs of conquering generals had ceased and were only an imperial prerogative. The field itself had been transformed from a marshland to a thriving center of entertainment and recreational activities. At that point in Rome's history, the story of Romulus's apotheosis could only confirm the Campus Martius as part of the city's foundation myth. Conclusions regarding the field's mythical significance during the early and mid-republican periods require consideration of the development of the stories surrounding Mars and Romulus.

Mars and his Field

As a deity worshiped by the Romans, Mars appears to date to the beginning of the republic in the late sixth century B.C.E. and, perhaps, even earlier to the monarchy. A stone inscription dedicated to Mars likely dates to circa 500 B.C.E.,66 and an ancient college of priests, the Arval Brotherhood, invoked Mars in the earliest surviving extended Latin text.67 By the early third century B.C.E., his image began to appear on coins.68 “Mars” may have been derived from various iterations of the name such as “Mavors,” “Mamers,” and “Marmor” found throughout the Italian Peninsula.69 The god was extraordinarily significant to the Romans, second only to Jupiter as their patron.70 Livy noted that Rome's second king, Numa, appointed flamines or priests for Jupiter, Mars, and Quirinus, and Ovid wrote that Mars was worshiped “above all gods.”71

The antiquity and significance of Mars to the Romans is found in his connection to the calendar, a connection that reflects on his ties to the Campus Martius. Mars was the only god in the old Roman calendar for whom a month was clearly named, and it was his month March that began the year.72 Until 153 B.C.E. consuls entered their official duties on March 1, the feriae Marti, commemorating the date when Mars's sacred shield, or ancile, fell from heaven.73 To celebrate this event, the members of the Salii Palatiniretrieved shields from the Regia in the Roman Forum and struck the ancilia with short spears or sticks as they marched through the streets of Rome singing hymns. This festival continued until the 24th of the month. On March 14, a horse race, the Equirria, was held in the Field of Mars. Although this was the first horse race of the calendar year, the Equirria was connected to a day of racing conducted two and a half weeks earlier (February 27), also on the Campus Martius. Both races were held in honor of Mars and, according to legend, had been initiated by Romulus.74 As described by Ovid, “The day has kept the appropriate name of Equirria, derived from the races which the god himself beholds in his own plain [in campo].”75 On the Ides of March another festival, Anna Perenna, was celebrated in the Campus Martius. Plebs would go out to the Field of Mars in pairs for a day of feasting and drinking, either in the open or in pitched tents.76 Likely derived for the term to complete the circle of the year, annare perennare, Anna Perenna was depicted as an old hag representing the old year while Mars represented the new. Mars was generally associated with the patrician class, and the holiday celebrated by the plebs mocked the war god who was tricked into making love to the ugly Anna.77 The last festival of the month of March was the Tubilustrium (March 23) during which military brass instruments were purified for use in summoning the comitia curiata, the curiate assemblies claimed to have been started by Romulus to validate the kings’ imperium and later the consuls’ imperium.78

Perhaps the most famous festival dedicated to Mars that took place in the Campus Martius was not celebrated in the month of March and was not even marked on the calendar. This was the ritual of the October Horse that took place on the Ides of October. Since the sixth century B.C.E.,79 two chariots, each pulled by two fast horses, would race at some still undetermined location in the Campus Martius.80 A horse of the winning racer would be sacrificed to Mars, killed, according to one ancient source, with a spear.81The tail and head were then cut off, with the former carried to the Regia so that its blood could drip on the sacred hearth and the latter fought over by two neighborhoods for the honor of displaying it.82 As early as 300 B.C.E., a Greek writer named Timaeus sought to explain the significance of the then centuries-old ceremony by relating it to the wooden-horse legend of the Trojan War.83

Attempts to connect these various festivals together and to draw conclusions about the nature of the Roman god Mars have generated contentious scholarly discourse. Some have cast Mars as an agricultural god, others as a god of war, and some historians have argued for both.84 Because the October Horse was characterized by at least two ancient writers as a “war horse” and the race occurred at the end of the campaign season, the sacrifice has been interpreted as a lustrum for the army as it lay down its weapons for the winter. It was tied, according to this theory, to the Equirria that opened the military campaign season.85 It has also been suggested that the October Horse was associated with the harvest season and that Mars was from earliest times an agricultural deity whose name was invoked in lustrations for farmers.86 The two theories are not mutually exclusive. The October Horse may have started as an agricultural harvest custom that changed over time to celebrate the end of the military season, “just as Mars originally perhaps the protector of man, herds, and crops alike becomes…a deity of warriors and war horses of the yearly renewed strength of a struggling community.”87 For the purposes of this study, what is most significant is that for as long as Romans were gathering in the Campus Martius to go to war and to return from battle, festivals were celebrated there in honor of Mars, creating and continuously reinforcing a special, sacred link between the deity and the space.88

Despite the long association of the campus with military activities as well as with festivals connected to the war god, structures dedicated to Mars appear to have been few. There is thought to have been an altar to the war god (Ara Martis) in the Campus Martius, but no temple is known to have been associated with it.89 The date of the establishment of the Ara Martis is unknown, although the writer Festus claimed it went back to the time of King Numa in the late eighth century B.C.E., 250 years before the first verifiable monument to Mars.90 No remains have yet been found, nor has its location been definitively determined, but a reference in Livy to the construction of a portico in 193 B.C.E. from the Porta Fontinalis to the Ara Martis suggests by context that the altar was in the area of the Villa Publica (Plan 2, No. 5).91 Livy noted that newly elected censors “as the custom was from olden times, took their seats on curule chairs by the altar of Mars.”92 As elusive as its location and age of construction is the date of the altar's disappearance. One historian believes that the Ara Martis was rebuilt after the fire of 80 C.E. and was located in the Divorum, the then remaining space of the earlier Villa Publica (Plan 4, No. 9).93

The first known temple dedicated to Mars and associated with the Campus Martius was erected circa 133 B.C.E. by Junius Brutus Callaicus.94 According to Pliny, it contained giant statues of Mars and of Venus, both by the famed fourth-century B.C.E. sculptor Scopas, and was located in the Circus Flaminius.95 If the Circus Flaminius is understood to be part of the Campus Martius, then Cassius Dio's report that “the temple of Mars in the field of the same name was struck by lightning” in 9 C.E., may refer to Callaicus's temple (Plan 3, No. 23).96 Nearby and just south of the Circus Flaminius was a temple of Bellona, a goddess of war, vowed in 296 B.C.E. by Appius Claudius Caecus, the builder of the Appian Way (Plan 2, Inset C).97 Although her name derives from the Latin word for war (bellum), Bellona is not precisely a female counterpart to the war god Mars. Mars was the personification of physical combat as was Bellona, but she was involved as well in war preparation, diplomacy, and war victory.98

Writing in the first century B.C.E., the Roman architect Marcus Vitruvius Pollio advised that “the temple of Mars should be…out of the city, that no armed frays may disturb the peace of the citizens, and that this divinity may, moreover, be ready to preserve them from their enemies and the perils of war.”99 Certainly, the Campus Martius met this Vitruvian principle for the placement of a temple of the god of war, but it was not the only place that worked. Two hundred fifty years before the Temple of Mars in the Circus Flaminius was built, one to the war deity was founded on the southern side of the city along the Via Appia. It was by this temple, vowed by T. Quinctius when Rome was under attack from the Gauls and dedicated in 388 B.C.E., that, thirty-eight years later, the Roman army was levied before a campaign just south of the city outside the Porta Capena. This same location served as the beginning point for a parade of the equites every July.100

Why was the northern plain not selected instead by Quinctius for his temple, or chosen by later generals to honor the war god until Callaicus built his temple in the Circus Flaminius in the late second century B.C.E.? As we will explore in the next chapter, the location chosen for temples depended in large part on the idiosyncratic agendas of the patrons, and in part on the evolving identities of the deities honored with such structures. Mars may have been avoided, in part, for the reason noted by one author that the god produced a blind fury, and hence bore the epithet Mars caecus. Such ferocity needed to be directed to victory, and “with the outcome still in doubt, the general appeals to a divinity less involved in the intoxicating detail of action.”101 At least in the fourth centuryB.C.E., the dearth of temples of Mars in the northern field, or those to any other deity for that matter, may also have had something to do with contemporary perceptions of the campus as an area that was best left open for military use. Until the beginning of the third century, the only known structures in campo were the Temple of Apollo Medicus at the far southern edge and the open space associated with the Villa Publica and the nonstructural saepta voting precinct (Plan 2, No. 3 and Inset C). By the mid-third century B.C.E., however, temples were being constructed in the central Campus Martius (the modern Largo Argentina), thereby diminishing any possible restrictions to building a temple of Mars simply on the grounds that the open space was needed for military assemblies (Plan 2, Inset A).

One author suggests that it was the early Ara Martis itself that provided the Field of Mars its name and since, as Ovid indicates, the entire field was the domain of Mars, arguably additional temples were unnecessary.102 Ovid, however, was writing at the turn of the first century C.E., and there is little to support the conjecture that an altar from centuries earlier provided the eponymous reference to the entire field or that ancient sacredness obviated any further need for a temple of the war god. The perceived lack of a temple of Mars may have been why Suetonius indicated that Julius Caesar intended to build one on the spot of his naumachia.103 Although the basin was filled after Caesar's death, the temple was never built.104 In short, despite the space's significance to the military, the available evidence suggests that no republican general commissioned a temple of the war god in his own field until the second century B.C.E., after numerous other deities had a claim to real estate in the Field of Mars.

Romulus on the Campus: Appearance and Disappearance

It has been conjectured that Rome's founding by twins is a tale of the mid- to late fourth century B.C.E. created in conjunction with laws that successively allowed power sharing between patricians and plebeians (367 B.C.E.) and then required a consul be elected from each group (342 B.C.E.).105 In 300 B.C.E., the brothers Gnaeus and Quintus Ogulnius, serving as tribunes, pushed through a law that permitted plebeians to have representation equal to patricians in the pontifical and augural colleges.106 It was under the direction of the Ogulnii brothers that the road out to the Temple of Mars on the Via Appia discussed earlier was paved. That temple is known to have had a statue of Mars accompanied by wolves in 217 B.C.E., although it is not known if they were she-wolves.107Livy notes that in 295 B.C.E. the brothers also set up a statue of the she-wolf with the “infant founders of the city” by the fig tree where they were exposed.108 This monument of the suckling twins who founded the city may be viewed as a celebration of the new equality.109 A quarter century later in 269 B.C.E., coins depicting a she-wolf were being minted (Figure 4). During approximately the same period, a Greek writer in Syracuse made the first known literary reference to Rome's founding by Romulus and Remus.110

4. Silver didrachm (third century B.C.E.). Reverse: She-wolf and suckling twins Romulus and Remus. British Museum. (Photo: © Trustees of the British Museum)

Early in the development of the legend of Rome's founding, Romulus and Remus were connected to Mars. The war god was viewed as a force of nature and had ties to both wolves and woodpeckers, animals that figure in the legend of the twins being saved at birth.111 In the same passage in which Livy describes the monument of the she-wolf and twins erected by the Ogulnii, he notes the brothers’ construction of the paved walkway to the Temple of Mars on the Via Appia.112 Romulus and Remus became identified as sons of Mars through the rape of their mother Rhea Silvia, a story that was told circa 200 B.C.E. by the historian Fabius Pictor.113 The twins were also subjects of two plays by the historical dramatist Naevius, who wrote sometime after 220 B.C.E., one on the birth and raising of Romulus and Remus and the second on the overthrow of Amulius.114 By the end of the first century B.C.E., the tradition was firmly established.115 Later Plutarch would claim that in order to honor Mars, Romulus, in turn, had named the month of March after the deity.116 Images of the twins with the she-wolf were common throughout the imperial era (Plate II and Figure 5).

5. Altar relief from Ostia depicting she-wolf nursing Romulus and Remus with personification of Tiber and shepherds (late first century–early second century C.E.). Museo Nazionale Romano, Rome. (Photo: Album / Art Resource, New York)

Plate II Fresco from the family tomb of Titus Statilius Taurus (late first century B.C.E.) of the infants Romulus and Remus in a basket by the Tiber

The temple of Quirinus, the divine name for the deified Romulus, located on the Quirinal Hill, was vowed in 325 B.C.E. and dedicated in 293 B.C.E., and it has been conjectured that the story of the death and apotheosis of Rome's first king was created in conjunction with the dedication.117 The epic poet Ennius (ca. 239–169 B.C.E.) noted that Romulus lived in heaven with the gods who gave him birth.118 It is unclear as to when the details of the location of the death in the Campus Martius were added, but they probably were established by the time Fabius Pictor wrote at the beginning of the second century B.C.E., roughly the same period that the story of Rome's founding had become canonical.119

Writers in the Augustan age supply two details for the location for Romulus's apotheosis on the Field of Mars. The first account suggests that Romulus's death occurred while he was reviewing his troops outside of the city.120 As noted previously, the likeliest place for this activity would be the Campus Martius, possibly in the area of the Villa Publica.121 The second clue is that the apotheosis occurred in campo ad Caprae paludem, or “in the Campus Martius, near the swamp of Capra,”122 an area identified as the low area in the central Campus Martius that would later become the site of Agrippa's Pantheon and the earlier Villa Publica.123 Romulus's legendary death on July 7, the Nones of Quintilis, may have been selected to coincide with a preexisting holiday, the Nonae Capratinae. On the other hand, the Nonae Capratinae may have been established to celebrate the site of the king's apotheosis. Plutarch's text allows for both possibilities. In one account in Plutarch, on the Nones of Quintilis, handmaidens, dressed in the clothes of their mistresses, ran out to the Campus Martius, conducted a mock battle, and then dined in huts constructed of fig tree branches while waited on by matrons.124 According to Plutarch, the holiday may have obtained its name from the wild fig or caprificusand was an ancient festival, still celebrated in his day.125 The alternative theory for the holiday's history in Plutarch is that the Nonae Capratinae was derived from the word for she-goats or caprae, which was also the name of the marsh where Romulus disappeared into a cloud, and therefore the festival celebrated his apotheosis.126 If that were the case, the Nonae Capratinae could not go back further than the middle of the fourth century B.C.E. when the Romulus legend probably developed. More likely, the date for Romulus's death was picked to correspond to a preexisting holiday, which, as two scholars have noted, was a day of “dissolution and reversal.”127 Certainly by the death of Augustus in 14 C.E., the holiday celebrated on the Field of Mars carried associations with both the death of the son of Mars and military victory.128

If the legend of Romulus's apotheosis was established alongside the dedication of the temple of Quirinus at the beginning of the third century B.C.E., it appears that the story was further embellished during the first century B.C.E. with the added detail of the resurrection of Rome's founder. According to Plutarch, after his apotheosis, Romulus was seen walking along a road by a patrician Julius Proculus. Romulus told Proculus that he was returning to heaven as the deity Quirinus, a name that Plutarch confirms was associated with the god Mars.129 An early first-century C.E. inscription makes clear the accepted deification.130 In Ovid's account of the tale, Romulus appeared dressed in a robe and announced to Proculus, “Bid the pious throng bring incense and propitiate the new Quirinus, and bid them cultivate the arts their fathers cultivated, the art of war.”131 When the Salii Palatini danced through the city streets in the month of March beating the ancilia, they were divided into two groups, one representing Mars, the other Quirinus.

Although Roman historians during the early empire recognized these myths as “fabulous,” they were not willing to dismiss entirely their historical authenticity. As Plutarch notes, “Although most of these particulars are related by Fabius and Diocles of Peparethus, who seems to have been the first to publish a ‘Founding of Rome,’ some are suspicious of their fictitious and fabulous quality; but we should not be incredulous when we see what a poet fortune sometimes is, and when we reflect that the Roman state would not have attained to its present power, had it not been of a divine origin, and one which was attended by great marvels.”132

Clearly, however, the tales were employed and sometimes embellished for political expediency. The tale of Romulus's resurrection dates back only to the mid-first century B.C.E., and the use of the name of the patrician Julius Proculus suggests it may have been fabricated to promote the ties between Rome's founder and Julius Caesar and his family.133 Julius Caesar appears to have attempted to capitalize on another part of the Romulus legend, namely, the connection between Rome's founder and the Trojan wanderer, Aeneas. During the late fifth century B.C.E., a Greek historian, Hellanicus of Lesbos, wrote that Rome was founded by Aeneas and named after “Rhome,” a refugee from Troy, who, along with other Trojan women, burned their ships on the Italian Peninsula to end the voyage.134 By the fourth century B.C.E. Roman patrician families were claiming Trojan descent.135 Roman incorporation of the story of Aeneas into the city's foundation legend is thought to date to the third century B.C.E.136 Fabius Pictor linked Aeneas with Rome's founders by establishing a chronology of several generations between the Trojan and the founder of Alba Longa and his descendants, the twins Romulus and Remus.137 The relationship varied over time, with a contemporary of Fabius Pictor believing Romulus to be the grandson of Aeneas, while an ambassador to Rome in 193 B.C.E. wrote that Aeneas had four sons, two of whom (Romulus and Remus) founded the city.138 By the first century B.C.E., the story was firmly established, with Livy documenting the death of Aeneas, the founding of Alba Longa by his son Ascanius, and the reign of his grandson Silvius and his descendants down to Rhea Silvia and her twin sons.139 The tradition was carried further by Strabo, Ovid, Plutarch, and, of course, Vergil.140 With the connection of Rome to Aeneas in full force by the time of his political ascendancy, Caesar drew the genealogical line down to gens Iulia. Before battle Caesar sacrificed to the mother of Aeneas (Venus) and to the father of Romulus (Mars), and after his defeat of Pompey the Great, he traveled to Troy.141 The associations of the Iulii with Rome's founders were amplified, as discussed later, by his adopted son and successor Octavian/Augustus.142 As a paean to Augustus, Vergil's Aeneid tied it together by predicting the future grandeur of Rome under the Iulii: “Wars shall cease and savage ages soften…Quirinus with his brother Remus, shall give laws.143 Romulus became Quirinus reunited with his brother in peace, both the sons of Mars.144 The story of Romulus and the founding of Rome remained an important theme throughout the imperial era.

The Name of the Field

Although it has been suggested by some modern scholars that an altar to Mars provided the name for the campus, Romans of the early imperial era associated the topographical name with an episode in the early history of the city. According to Livy, the Field of Mars received its name when the land “lying between the city and the Tiber” was seized in 509 B.C.E. from Rome's last king, Tarquinius Superbus, after his followers attempted to regain for him the throne and his royal property. When the revolt failed, his lands outside the city walls were seized and “consecrated to Mars and became the Campus Martius.”145 Plutarch states that it was the better part of the campus that had belonged to Tarquinius Superbus and was dedicated to Mars, which suggests, perhaps, that the former king's lands did not include the entire field.146

The property was seized at harvesttime and because, according to Livy, religious reasons forbade the consumption of the crop that grew on it, the grain was then cut to the ground and tossed in the Tiber.147 Plutarch suggests that the consecration to Mars came first, and, therefore, it was that act that made the grain holy and unfit for consumption.148 He further notes that not only the sacred grain but also entire trees on the former monarch's grounds were cut down, an act that left the place “wholly untilled and barren for the god of war.”149 The grain cast in the river became stuck in the mud of the low summer flow and blocked the passage of other flotsam that then accumulated over time and formed the Tiber Island.150 The story reverberates in the July celebration on the Campus Martius of the Nonae Capratinae that occurred just before the grain harvest when “an abundant crop could guarantee once again the maintenance of the social order.”151

Although Livy claims that the property's eponymous reference to the war god gained currency at the time of the expulsion of the last king of Rome, he also uses the phrase in campo Martio to describe the space when used by an earlier king Servius to hold the first census.152 The anachronistic reference by Livy may not be surprising when it is considered that extant texts indicate that ancient historians writing about Rome, both Greek and Roman, used only the words campus and its Greek equivalent pedion(πεδιον)without the additional reference to Mars until the mid-first century B.C.E.153 Even then campus with the addition of Martius is not consistently used.154

Why were ancient references to the plain as the Field of Mars only recorded relatively late? It may have been that the space was already intimately connected to the war god through musters, triumphs, holiday celebrations, and an altar; the full name could go unstated in the same way that telling a neighbor that one is going to the “mall” conveys sufficient information as to its location without using the formal title. This was, after all, the largest open “field” outside the city walls, and its use for gatherings of soldiers and ceremonies tied to Mars went back hundreds of years. There is, however, another possibility. As we saw in the overview of the area's development in the preceding chapter, and as will be discussed in more detail later, by the mid- to late first century B.C.E., the once empty space was beginning to fill with structures. It did not look so much like a “field” as it had in the past centuries, except perhaps in its northern reaches, and activities connected with war and Mars were waning. Troop assemblies on the plain were diminished, if not completely eliminated, and triumphal parades, such as Pompey's great triumph of 61 B.C.E., while still spectacular, were fewer and further between. The structures connected with Mars and the martial activities of the troops and triumphant generals were therefore reduced to the point that perhaps the term “field,” as a shortened version of the more descriptive “Field of Mars” was seen as insufficient.

At the same time, however, new associative links were being forged. Various foundation myths connecting Mars, Romulus, and even Aeneas to one another gradually obtained canonical status. Such connections were ripe for exploitation by those Roman leaders vying for enhanced political power at a time when the traditional republican institutions of government were waning. Pompey crowned his new theater with a temple dedicated to Aeneas's mother, Venus Victrix, while Caesar, who tied his family to the Trojan hero, answered Pompey's grand structure with plans for the massive Saepta Julia. It is argued that Caesar even wanted to straighten the Tiber to increase the size of the Campus Martius, and as noted earlier, he possibly planned to fill in his naumachia in the western Campus Martius and to construct a temple of Mars.155 To further emphasize his ties to Rome's founders, Caesar was reported to have dressed in the manner of Romulus and set up a statue of himself in the temple of Quirinus, the deified Romulus.156 The dictator also took the title pater patriae, likely in reference to Rome's founder who had the title pater.157 These associations were not lost on the writers of the day. Cicero, who, as we have seen, was now adding the word “martius” to “campus,” took umbrage at Caesar for equating himself with Quirinus.158

Caesar's successor, Augustus, visualized his connections to Rome's foundation legends by embroidering them on the urban fabric. In 16 B.C.E. the emperor restored and rededicated a temple of Quirinus that displayed sculptures on its pediment of Romulus and Remus taking auspices (Figure 6).159 Twenty-seven years earlier, still with the name Octavian, Augustus had marched up the Via Flaminia to the city walls, and on August 19, 43 B.C.E., Caesar's heir was first elected consul in the Campus Martius. It was in the Campus Martius, according to Cassius Dio, that Augustus saw six vultures present during a meeting with citizens, and then another twelve appeared to him while he was addressing the army. “Comparing [the sight] with Romulus and the omen that had befallen him, [Augustus] expected to gain that king's sovereignty also.”160 Augustus eventually brought the war god within the city limits with the construction of the Temple of Mars Ultor (Mars the Avenger) in the Forum of Augustus, finally dedicated in 2 B.C.E.161With its eight Corinthian columns lining the facade, the temple portico contained freestanding sculptures of both Romulus (“carrying on his shoulders the arms of conquered leaders”) and Aeneas (“and many an ancestor of the noble Julian line”).162 The pediment displayed Mars in the center and a seated figure of Romulus.163 In addition to his new grand temple of Mars, Augustus rebuilt the temple of Jupiter Feretrius on the Capitoline, a temple thought to have been erected by Romulus that contained the first king's spoils of war (spolia optima).164 Down in the area of the Circus Flaminius, Augustus also rebuilt the temple of the goddess of war, Bellona. On the Palatine, he constructed a house near the so-called hut of Romulus, an eighth-century B.C.E. timber and thatch structure that the Romans believed was the first king's archaic home. By the Palatine's southwestern slope, he repaired and monumentalized the cave where legend recorded that the she-wolf had once suckled and protected Romulus and Remus.165Augustus's important generals also apparently desired to be associated with the legends of Rome's founding. Frescoes discovered in the tomb of the commander of Augustus's land forces at Actium, T. Statilius Taurus, narrate the foundation cycle from Aeneus to the twins (Plate II).166

6. Relief fragment depicting the pediment of the Temple of Quirinus (late first century C.E.). (Photo: with permission of the Ministero dei beni e delle attività culturali e del turismo – Soprintendenza Speciale per i Beni Archeologici di Roma)

Augustus's extensive public building program was executed in large part by Marcus Agrippa, a man both Vergil and Propertius appear to have associated with the mortal Remus in his close partnership with Augustus, the immortal Romulus.167 Agrippa's original Pantheon was located in the area of Romulus's ascension from the Caprae Palus and may have contained a statue of Rome's founder.168 Writing more than two centuries after Agrippa's construction, Cassius Dio, who was clearly confused about some elements of Agrippa's Pantheon, nevertheless recorded that the Augustan structure also contained cult statues of Mars and Venus,169 which indicates that the original building may have been dedicated to those deities.170

Another Augustan monument in the Campus Martius closely associated to the foundation legends was the altar to Augustan peace, the Ara Pacis Augustae. After Augustus's return from Gaul and Spain in 13 B.C.E., the Senate decreed the monumental altar's construction. It was erected along the Via Flaminia in the northern Campus Martius and dedicated on January 30, 9 B.C.E. Although the identification of the friezes on the reconstructed altar is not beyond doubt, the northwest panel on the exterior of the precinct wall has generally been interpreted as depicting the discovery of the infants Romulus and Remus by their adoptive father Faustulus, with the god Mars in attendance.171 The southwest panel has generated more controversy with a long-standing scholarly tradition identifying the main figure as Aeneas in the act of sacrificing a sow.172 Thus, Augustus, through both panels, is tied to the canonical foundation stories. Recent scholarship has argued, not without disagreement, that the veiled and bearded figure traditionally identified as Aeneas is instead an image of Rome's legendary second king, Numa Pompilius.173 If Numa rather than Aeneas, the figure would have nevertheless reinforced important associations of Augustus with the Campus Martius and Rome's early legends. As noted earlier, Roman writers attributed the construction of the Ara Martis in the Campus Martius to Numa; it was at the Ara Martis that Numa sacrificed to Mars to honor the treaty between the Sabines and the Romans. In addition, Numa enacted a law that established the rules for going to war and the use of the fetiales described previously.174 Whereas Romulus was the warrior king, Numa was viewed as a peacemaker. The Campus Martius was the space from which Romans for centuries thereafter marched to war and usually returned in victory and the concomitant cessation of hostilities. Augustus returned to the Field of Mars having vanquished his enemies and ushered in an era of peace. A reinterpretation of the Ara Pacis's southwestern mythological panel as a scene depicting Numa does in fact create a more balanced iconographic presentation of the attributes of Rome's first emperor.175

Even the imperial title of Augustus taken by Octavian was associated with Rome's founder. Although according to Suetonius it was suggested that Augustus receive the title of Romulus as a “second founder of the city,” the appellation was rejected, likely because it carried monarchical connotations.176 Nevertheless, the nomenclature of “Augustus,” selected as “not merely a new title but a more honorable one,” was believed by Suetonius to have had an etymological connection to the auguries by which Romulus was chosen as Rome's first leader.177 According to Ovid, Augustus's achievements had now surpassed those of the founder of Rome, and so Ovid noted that Romulus “must yield pride of place” and the title “Father of the World” (pater orbis) to the first emperor.178 The concept of Augustus as successor to Romulus and worthier of praise than Rome's founder did not end with the death of the first emperor. Augustus died on August 19, 14 C.E., the anniversary of the date he was first elected consul and that of his own reported experience of the vulture augury tied to the selection of Romulus. Images of Augustus's prominent ancestors “beginning with Romulus himself” were carried in his funerary procession.179 In his funeral oration, Augustus's adopted son and successor, Tiberius,praised the accomplishments of the first emperor of Rome: “Yet what deed like this can be cited of Alexander of Macedon or of our own Romulus, who perhaps above all others are thought to have performed some notable exploit in youth?But these men I shall pass over, lest from merely comparing them with him and using them as examples – and that among you who know them as well as I – I may be thought to be detracting from the virtues of Augustus.”180

In a clear allusion to the apotheosis of Romulus, Cassius Dio describes how the deceased emperor was transported on a bier through the Campus Martius where his body was consumed in the flames of a funeral pyre and “an eagle released from it flew aloft, appearing to bear his spirit to heaven.”181 Even the story of the sighting of the deceased Romulus is retold with Augustus in the place of Rome's founder. Dio notes that his widow Livia “bestowed a million sesterces upon a certain Numerius Atticus, a senator and ex-praetor, because he swore that he had seen Augustus ascending to heaven after the manner of which tradition tells concerning Proculus and Romulus.”182 At about the same time, the self-penned list of deeds by the emperor, the Res Gestae, was affixed to his Mausoleum in the northernmost reaches of the plain. In the Res Gestae, Augustus referred to the location of the Ara Pacis Augustae as the Campus Martius.183


Although Livy recorded that the apotheosis of Romulus in the presence of his troops occurred in the eighth century B.C.E., evidence suggests the legend did not start circulating until four centuries later. Before the fourth century B.C.E., the northern plain likely had associations with Mars, but not with the foundation legends. The links to Mars were probably made especially strong through the field's use for musters, triumphs, and military festivals and, possibly, its altar. It was not, however, unique in that regard. The area just south of the city walls along the Via Appia contained a temple of Mars and served as a gathering place for troops as early as the fourth century B.C.E. By the third century B.C.E., the connections of the mythical founders of Rome with Mars and to the space north of thepomerium were slowly strengthening. Concurrently, the requirement of a large open plain for war preparation was diminishing. Armor that had been donned for protection before battle was relegated to costume for mock military engagements, and thenavalia gave way to the entertainment venue known as the naumachia. What open space remained in the early imperial era, mostly in the northern portion, was used in a simulacrum of warfare, not in preparation for the real thing. Suetonius provided the following description of a mock battle by the emperor Claudius: “He gave representations in the Campus Martius of the storming and sacking of a town in the manner of real warfare, as well as of the surrender of the kings of the Britons, and presided clad in a general's cloak.”184

Indeed, there appears to have been an inverse relationship between the use of the area for war footing and its mythological ties to the war god and the glorification of military engagement. The manifestations of those connections of Mars to the northern field, however, were gradual and relatively late in date. Apart from the possible Ara Martis, the first religious structure reliably dedicated to Mars to be built in these northern reaches was not constructed until late in the second century B.C.E. Even then the first temple to Mars was raised only on the area's edge in the Circus Flaminius, notwithstanding the fact that throughout the middle and late republic the Campus Martius was the preferred site of numerous manubial temples. The failure to honor the war god properly in his own field may have been recognized by Julius Caesar around the same time that writers began identifying the space formally as the Field of Mars. In the late republic, Rome's foundation legends were made more immediate through various fictitious genealogical connections to the city's leading families. As the republic transitioned into an empire, little could be seen of the empty plain where Cincinnatus had once ordered Rome's youth to gather with spears at sunset. The marshland had been filled with temples, theaters, and amphitheaters but was recognized clearly as the Campus Martius, the Field of Mars.

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