APPENDIX B
Unlike present-day armies, which have intakes of recruits on an ongoing basis, from republican times the men of the Roman legions were all recruited into their units at the same time, in mass intakes. It was exceptionally rare for replacements to be brought into a legion during the course of an enlistment, unless, as in the case of the 14th Legion in 54 B.C., it was to replace an enlistment that had been completely wiped out in battle. Sometimes, by the end of an enlistment period, particularly if the legion had suffered heavy casualties during its sixteen- or twenty-year enlistment, a legion could be significantly understrength.
The recruiting of auxiliary units was much more haphazard, as auxiliaries were not Roman citizens and did not have the protection of Roman contract law like legion recruits, who signed a binding contract with the state on enrolling with their legion. New auxiliary units were frequently recruited as and when required, with the new units put at the disposal of the legions, particularly those legions that were understrength, to serve alongside them in particular conflicts as support units.
The Augustan legions were all originally founded by Pompey and Caesar, but not at the same time—their foundation went back to 84 B.C. for the 1st Legion and the 2nd Augusta Legion, through to 49 B.C. for the last of the original twenty-eight legions. As a result, reenlistment years varied, legion by legion. Down through the ages there were years when no legions underwent reenlistment, and years when several reenlisted at the same time because they had been founded in the same year. For example, the 6th, 7th, 8th, and 9th Legions were all founded in Spain in 65 B.C., and subsequently would have always reenlisted in the same year down through the centuries.
Until the time of Augustus, legionaries served for sixteen years. During his reign, the legions moved to twenty-year enlistments. By knowing the year in which each legion discharged its veterans and enrolled a new enlistment of legionaries, it is possible to garner a great deal of information about each unit.
It is not difficult to determine the establishment and reenlistment dates of just about every legion and of the Praetorian Guard, from data in historical texts. This information allows us to pinpoint legion movements and locations. For example, by using the reenlistment factor, it becomes clear that legions were frequently transferred to new assignments at the end of their enlistment periods, so that new recruits started fresh at the new post.
On discharge, legionaries were often set up in military colonies in the province where they were serving. These military colonies frequently grew into major cities, such as Cologne in Germany, Colchester in Britain, and Beirut in Lebanon. By correlating the date a colony was established with the date of legion discharges and reenlistments, we can identify the legion that provided the veterans for each settlement. This allows us to know for example, that the first legionary settlers of Cologne were from Switzerland, that the settlement at Colchester was made by ex-soldiers from northeastern Italy, and that Spaniards from the Córdoba area originally settled Beirut. By reversing this process, we can confirm that a particular legion was serving in a particular province at a particular time.
By correlating the reenlistment factor with changes of provincial governors, we can see that new gubernatorial appointments frequently took place at the time of the reenlistment of legions based in their provinces. This may have been coincidental, or deliberate policy of the Palatium.
It also seems that new intakes were usually recruited several months in advance of the discharge date of the veterans they were replacing, to allow time for the recruits to march from the recruitment ground to the legion’s station and undergo basic training before the veterans retired from the legion. Sometimes legions were left understrength when veterans were discharged on the due date, ahead of the arrival of the new intake of recruits. For example, the latest enlistment of the 20th Valeria Victrix Legion apparently hadn’t arrived in Britain after its veterans had been discharged in A.D. 60, and this may have led to the Boudicca Revolt taking place when it did. Boudicca also would have known that the 9th Hispana Legion had only just received a new intake of green recruits from Spain, youngsters who were soon annihilated.
A study of the reenlistment dates of the legions also tells us that the changeover from sixteen-year enlistments to twenty-year enlistments was phased in by Augustus between 6 B.C. and A.D. 11, as each individual legion’s latest reenlistment fell due.
By knowing that a particular legion reenlisted in a particular year, we open a whole new door to our understanding of the legions. When the 12th Legion performed so badly against the Jewish partisans in Judea in A.D. 66, losing its eagle and taking heavy casualties, it had much to do with the fact that the legion was due for reenlistment in the new year and its youngest legionaries were thirty-nine years of age while its senior cohorts were manned by men no younger than fifty-nine, all thinking about their looming retirement and neither mentally nor physically equipped for the serious fighting they would encounter—the last men an astute commander would choose as the main element of his combat force.
By using the reenlistment factor, we can determine that the recruits snared by Piso at Celenderis in A.D. 19 after the assassination of Germanicus Caesar were Greek or Spanish youths bound for the 4th Macedonica or 6th Victrix Legions in Syria, which were both due for reenlistment in the new year.
The reenlistment factor even allows us to calculate the ages of many legionaries in any given year, because all new recruits were a minimum of twenty years of age on entry into the imperial legions. If a legion underwent its latest reenlistment three years ago, say, then this year many of its legionaries would be twenty-three, some would be forty-three, and one or two would even be sixty-three. The ages of centurions are less easy to calculate, because they moved around among the legions as they were promoted, and the legion they started with might well have a different reenlistment date to that of their current legion.
The reenlistment factor allows us to determine that the four 12th Legion legionaries who carried out the crucifixion of Jesus Christ were quite possibly forty-one-year-olds who’d recently commenced a second enlistment with their legion—the senior 2nd or 3rd Cohorts would have been posted to troublesome Jerusalem; besides, second-enlistment men would have earned the perks that went with carrying out executions—and that the men of the 3rd Augusta Legion who escorted St. Paul to Rome in A.D. 60–61 were probably raw recruits who’d just joined the legion.
Thanks to Roman efficiency and consistency, we are able to use the reenlistment factor in furthering our knowledge and understanding of the Roman Empire and its legions.