HANNIBAL WAS ACROSS the Alps, but all the effort up to this point had done no more than to place him in a position to begin the assault on his real enemy. The cost of getting this far had been enormous. For the moment his soldiers were exhausted by their privations, incapable of effective operations until they had been rested and fed. Very few of them were left: only 6,000 cavalry and 20,000 infantry - 12,000 Libyans and 8,000 Spanish - were still with the colours when the army came down from the mountains. Hannibal had been followed into Gaul by 9,000 horse and 50,000 foot; 8,000 and 38,000 respectively had crossed the Rhone, so in the course of a few months he had lost more than half of his army. Only a small minority of these losses were battle casualties. It has sometimes been claimed that large detachments were left behind to control the Gallic tribes and ensure the safe passage of future reinforcements and supplies from Punic Spain, but there is no good evidence for this and our sources never mention such garrisons in later narratives of the war. Nothing in Hannibal's later behaviour suggests that he expected to remain in constant communication with his base in Spain. When his brother Hasdrubal attempted to bring a reinforcing army into Italy in 215 and 207, he marched it in an expedition reminiscent of Hannibal's original invasion. It is possible that the large numbers for the earlier phases of the campaign are exaggerated, and certainly Polybius does not seem to attribute them to the same impeccable authority of the Lacinian inscription, but all our sources were convinced that Hannibal's losses before he arrived in Italy were substantial, especially during the crossing of the Alps, so it is probably best to accept them. Once again, the vast majority were probably deserters or young recruits unable to keep up on the long marches. (During Napoleon's invasion of Russia in AD 1812, it was the young conscripts who were first to give way under the strain of the rapid advance, quickly thinning the ranks of his massive army.) We should note that only 40 per cent of the infantry to reach Italy were Spanish, when these had probably formed the vast majority of the force which mustered in New Carthage earlier that spring. It is also interesting that the army's cavalry did not suffer as high a rate of attrition as the infantry, since as a rule horses break down before men. Hannibal's victories were to owe much to his numerically superior and well-disciplined cavalry and it is clear that they formed something of an elite. Perhaps they were more highly paid than the foot, and probably they were better motivated, but it is certain that Hannibal had taken great care to cosset his cavalry on the march. However, their horses must have been in a poor state and needed to be rested and properly fed. Hannibal may have lost the bulk of his soldiers in reaching Italy, but the ones he had left were the pick of the army, doubdess mainly the veterans of his family's Spanish campaigns.1
Hannibal had reached the northern Italian plain, descending in the tribal territory of the Taurini, roughly around modern Turin. He had two immediate priorities. The first, and most pressing, was to secure supplies of food for his men. The pack animals of the baggage train had suffered especially badly during the passage of the mountains, and it is extremely unlikely that the army was still carrying any significant reserves of food. His second concern was to recruit contingents of allied soldiers, for at present his forces were barely equivalent in size to a single consular army. Both needs could be supplied by the Gallic tribes of the area, but at first their response to his approaches was disappointing. Hannibal does not seem to have had any prior contact with the Taurini and the tribesmen were cur-rently too busy fighting their neighbours the Insubres to be interested in joining a Punic war against Rome. The Carthaginian army surrounded the main oppidum or hill town of the tribe, storming it after a three-day siege. The inhabitants were massacred in a calculated display of ruthlessness intended to overawe the tribes, and the winter reserves of food usually gathered in such setdements seized to be devoured by the army.2
At this point the surprising news reached Hannibal that Publius Scipio, whom he had not long ago encountered on the Rhone, was operating at the head of an army in the Po valley. It was not common for Roman consuls to abandon their own army to take charge of another and Hannibal had no way of knowing that in fact Scipio's troops had continued on to Spain, so it was natural to assume that somehow the Romans had achieved the unlikely feat of transporting their army back to Italy faster than he could march there. As far as he knew, this meant that an entire consular army had already been added to whatever troops he must have assumed the
Romans already had in the area and in due course these might be augmented by further reinforcements. This made Hannibal's need to gain more troops and supplies from the Gallic tribes even more imperative. The Gauls would not rally to an invader who did not seem confident and anyway some of the tribes most likely to join him, the Insubres and Boii, lived further to the east, in the direction of the Roman army. As soon as he considered his troops sufficiently rested, Hannibal advanced down the Po. Scipio displayed the same confidence he had shown in his earlier brief encounter with the enemy and led his troops out from Placentia to confront the invader. At this stage the advance of a strong Roman force was enough to deter the nearer tribes from joining Hannibal.3
Both commanders are said by our sources to have assembled their soldiers and given them an encouraging speech. Such addresses were a well-established feature of ancient historiography, a rhetorical device adding drama to the narrative as the author created an elegant version of what he felt a general should have said on such an occasion. It is unlikely, though not entirely impossible, that such speeches preserve anything actually said by the commanders. However, Hannibal is said to have employed one rather unusual means to inspire his men, which may well be accurate. The Allobrogian prisoners captured during the fighting in the Alps were asked whether any would be willing to fight each other to the death, with the promise that the victor would go free and take a horse and weapons with him. The Gauls, products of a warlike society where single combats were a common means of settling disputes and frequently occurred during feasting and other celebrations, all jumped at the chance of gaining not only freedom, but glory in the process. Polybius says that a pair of warriors were chosen by lot, Livy that many pairs were selected, and both agree that they were the envy of the remaining prisoners. The Carthaginian army watched the fight and saw the victor (or victors) riding away to freedom. Hannibal is supposed to have used this to illustrate their own situation, where they were faced with a simple choice between death and fighting hard and so gaining great rewards. If Livy is to be believed he promised his soldiers land and even Punic citizenship when the war was won.4
The two armies marched towards each other along the north bank of the River Po. Probably somewhere near modern Pavia, Scipio bridged its tributary, the Ticinus, constructing a roadway across a line of moored boats, the ancient equivalent of a pontoon bridge. The Romans were now marching through the territory of the Insubres. Two days later, each army's scouts reported the enemy's presence, the first solid information which either army received about the other's whereabouts. The armies halted and camped, immediately becoming more cautious in their movements now that the enemy was close. On the next day both commanders led out a strong force and went in person to reconnoitre. Hannibal had the bulk of his 6,000 horsemen with him, and Scipio was significantly outnumbered despite having all of his cavalry, including Romans, Latins and Gallic allies, but did have the support of some of his velites. The first indication that either group had of the other's approach were the clouds of dust thrown up by their hoofs. Both sides were confident and deployed ready to fight. Scipio placed his velites in front supported by his Gallic allies and kept the Italian cavalry as a reserve. Hannibal formed a centre from his close order horse, which was mostly Spanish, and formed the Numidians into two groups, one behind each end of his line, ready to flow around the enemy flanks.
Skirmishing between the cavalry and light troops was a common preliminary to battles in this period, often occupying a number of days and tending to be very tentative. Scipio's initial deployment suggests that he expected the fight to begin with a long exchange of missiles, the cavalry units advancing rapidly to throw javelins and then retiring just as quickly. Such fluid engagements, where the fortunes ebbed and flowed as fresh, formed squadrons were committed, were considered typical of cavalry actions in the ancient world. However, any such plans were rapidly abandoned as both commanders decided that this was an opportunity to gain an early victory, which would inspire the rest of their soldiers in the anticipated battle. Hannibal must have seen that his own horsemen significantly outnumbered the enemy, whilst Scipio may well have unwisely despised the enemy whom his cavalry had so recently beaten in the skirmish on the Rhone. Before the velites had come close enough to throw a single javelin, both sides' close order cavalry surged forward in a full-blooded charge. The surprised velites fled back through the intervals between the Roman squadrons as these advanced through them. The heavy cavalry met in the centre, where a fierce standing melee developed, unlike the usual flowing cavalry battle. Not for the first time we hear of some horsemen dismounting to fight on foot. Contrary to popular belief, the lack of stirrups was not a major handicap to ancient cavalry, since the Romans and probably the Spanish and Gallic cavalry of this time were already using the four-horned saddle which provides an admirably firm seat. Yet men on horseback were not suited to standing fast and fighting stationary mass against stationary mass, since, apart from sacrificing their main advantages of speed and momentum, the horses are always inclined to shy or bolt. A closely formed group of men on foot were better able to endure a long combat and hold their position. Such groups provided highly effective support for their mounted colleagues, providing secure protection to rally and reform behind before charging again. This is most probably what we should understand occurred at Ticinus. The poor state of many of the Carthaginians' horses after their long and arduous march may have further encouraged this combat to be less fluid and mobile than was usual.5
For a while the fight was indecisive, but then the Numidians flowed around the Roman flanks. The velites, already nervous, panicked and were ridden down as they fled, for scattered infantry have always been intensely vulnerable to enemy cavalry. Other Numidians charged into the rear of the Roman cavalry, putting them to flight. Probably in this later stage of the fighting, Scipio himself was badly wounded. Family tradition held that the consul was saved by his 17-year-old son, also called Publius, although one early version held that a Ligurian slave was responsible. In the more popular version, the youth had been given command of a troop of cavalry stationed in the rear, and charged alone to rescue his father, shaming his reluctant men into following him. The young Publius would later prove to be Rome's greatest general of the war, the man who would conquer Spain, invade Africa and finally win the only pitched battle Hannibal ever lost as a commander, so it is unsurprising that this version of the story has been preferred by most ancient and modern authors. A small group of cavalry clustered together around the consul and made their way safely back to the Roman camp.6
Hannibal still expected there to be a full-scale battle in the next few days, but Scipio was clearly overwhelmed by his defeat and resolved on an immediate flight. Polybius tells us that the defeat of his cavalry showed him that it was unwise to fight on the open ground north of the River Po. His men began to withdraw during the night and the Roman army hastened back to the Ticinus. Hannibal pursued them and captured 600 men from the party left behind to destroy the bridge of boats, but only after they had completed their task. Unable to cross, the Carthaginians turned around and marched for two days westwards along the Po, until they discovered a place where the engineers could build a bridge, allowing them to cross to the south bank.7
Scipio pulled back as far as his base at the colony of Placentia, where he rested his soldiers and cared for the wounded. The Roman army seems to have camped to the west of the River Trebia, on the opposite bank to the city. Two days after crossing the Po, Hannibal's army arrived and formed up for battle on the flat land in front of the Roman camp. They refused the challenge, so, with his men encouraged by the enemy's timidness, Hannibal set up his own camp about 5 or 6 miles away from them. This demonstration of Roman weakness had an effect on some of the Gallic allies in the camp. In the night a group of Gauls massacred the Roman soldiers sleeping near to them in the camp, beheaded them, and then deserted to Hannibal. The Carthaginian welcomed the 200 Gallic cavalry and 2,000 infantry who came across in this way, promising them rich rewards and sending them back to their tribes to raise further support. It was at this time that his expectations for aid from the tribes began to become a reality. Chieftains from the Boii arrived bringing the Roman commissioners they had captured in their attack on the colonies earlier in the year. Hannibal made a formal alliance with the tribe, returning the prisoners to them to use as bargaining counters to regain their own hostages held by the Romans.
Scipio's position was becoming more untenable as the enemy's strength grew. The day after the Gauls had deserted, the Roman army prepared to move under cover of darkness, setting out before dawn and crossing the Trebia. Scipio moved to the high ground which rises suddenly up from the otherwise flat plain either side of the river. Withdrawing when in close contact with the enemy has always been a hazardous operation and as soon as reports came in of the Romans' departure, Hannibal launched his Numidian horsemen in pursuit. The other cavalry were despatched to support them, followed by the remainder of the army under his personal charge. Luckily for the Romans, the North African tribesmen paused to loot and burn the abandoned camp. This may be a sign of indiscipline or an indication that food was still scarce in the Punic army. The delay allowed the Roman army and most of its baggage to get across the river in safety, but even so numbers of stragglers were rounded up or killed by the enemy when the pursuit resumed. Scipio probably camped near the modern village of Rivergaro and there waited for reinforcements.8
Ticinus was one of the smaller actions of the war, little more than a large skirmish, but had a special importance as the first encounter between the two sides on Italian soil. The effectiveness of Hannibal's numerically superior cavalry was amply demonstrated, as was the high degree of control he and his subordinates exercised over them. This victory and the precipitate Roman flight it caused ensured his army would be able to fight in Italy, since it confirmed the decision of several of the Gallic tribes to join him. Scipio's behaviour had been typically Roman in its straightforward aggressiveness. He had marched to confront Hannibal's army as soon as possible, before he had any precise figures for its size and strength. His behaviour before the cavalry flight makes it clear that he anticipated a battle which he expected to win. The shock of his defeat, and perhaps of his own wounding, shattered his confidence. Scipio may have been right in that the open land west of the Ticinus favoured Hannibal's cavalry, but in other regards it is improbable that the Romans were significantly outnumbered by the enemy infantry and they may even have had a slight advantage. Soon the enemy numbers were to grow as more and more Gallic warriors joined them. The speed with which the Romans fled destroyed whatever facade of strength they had presented to the tribesmen.