Hannibal

by Patrick N Hunt

  Back in Rome, where the Ticino outcome took the city by surprise, rationalization suggested that the outcome was due not to Hannibal—his name did not yet strike such fear—or Roman overconfidence or negligence but mostly Celtic treachery. The Romans trusted greatly in their infantry, “still unimpaired”2 after Ticino. When Tiberius Sempronius marched through Rome en route to meet up with Scipio, the premature consensus was that all Sempronius had to do was show up with his legions, and the outcome would be decided.

  Ticino also appears to be the first time in any warfare engagement that Hannibal employed what would become his famous trademark maneuver: the double envelopment that compressed and crushed the Roman infantry.3 Although Hannibal was always prone to tricks, feints, decoys, ambushes, and other stratagems, this incredibly effective use of his Numidian light cavalry was only offset perhaps by an overdependence on it at times. Regardless, however, of how many times he used it, it continued to flummox the Roman generals, whose own cavalry units were not as mobile.

  DIFFERENT PLANS OF SCIPIO AND HANNIBAL

  While Scipio holed up first in Placentia and then possibly at a new fortified camp south of Placentia after Ticino, hoping to wait out the worst of the winter, it appeared that Hannibal also wanted to delay further engagement in battle. On the other hand, it’s entirely possible that Hannibal was waiting to pounce on Sempronius instead. Most historians have agreed for centuries that Hannibal had eyes and ears—most likely Celts—in the Roman camps reporting on the division between Scipio and Sempronius.4 He may already have heard that the majority of Romans—excluding Scipio—were as overconfident as the impetuous Sempronius himself. Hannibal probably had spies in Rome providing him with this important information: Sempronius knew his consulship was running out by the next year, and any occasion to obtain glory must be taken quickly or not at all.5 He would play right into Hannibal’s hands.

  By mid-December of 218, Tiberius Sempronius Longus and his two legions had arrived in the Padana. They had traveled more than a month from Lilybaeum (near modern Trapani on the west coast of Sicily) in a maneuver combining sea and land to Ariminum on the northern Adriatic coast of Italy, mostly by foot using the Via Flaminia north from Rome; exiting Rome by the Flaminian Gate, it was the most direct Roman road to the Po and the new Roman colonies there. Although Livy claims they sailed all the way from Sicily,6 this is not likely given the lateness of year7 and the fact that Polybius states that they marched through Rome. There are many places where the accounts of Polybius and Livy cannot be reconciled.8 Polybius rarely errs on geography, partly because he traveled the routes himself, whereas Livy rarely did. Most historians prefer Polybius when differences occur unless there is a reason not to do so.9

  TIBERIUS SEMPRONIUS LONGUS

  After arriving in the Padana, Sempronius camped with his weary troops very close to Scipio’s camp, with both camps possibly near the modern town of Rivergaro, just east of the Trebia River. It is doubtful that Scipio was all that happy to see Sempronius with his two legions: in some way, his being there was an implicit criticism. In the following days, Sempronius prepared plans to fight Hannibal following meetings with Scipio, who tried to dissuade him from expediting a battle.

  Hannibal and Sempronius could hardly have been more different. Sempronius was mostly a politician bent on glory, while Hannibal was a soldier’s soldier, a leader who sought not personal but national gain. Elected consul in 218 by the Senate along with Publius Cornelius Scipio, Tiberius Sempronius Longus (260–210 BCE) was supposed to pressure Carthage directly. He was first sent to Lilybaeum to muster and ready an invasion force to Africa. Livy says that Sempronius was outfitted with 2 legions of infantry and regular cavalry, totaling 14,000 allied infantry, and 1,600 horse.10 He also originally had with him 160 quinquiremes for transport, although this may have been reduced to 60. Sempronius had been modestly successful in seizing the island of Malta from a Carthage that was preoccupied elsewhere. Scipio had been sent to Massilia in Gaul intending to reach Spain in order to head off Hannibal before he reached Gaul. Because he hadn’t been successful, he had quickly turned back to North Italy to await Hannibal’s exit from the Alps, leading to their encounter at Ticino.

  With Scipio wounded and in retreat from Hannibal, the Senate quickly recalled Sempronius from Sicily with his new legions, dispatching him to Padana. Because of Scipio’s near disaster at Ticino and Sempronius’ overrated victory in Malta, Sempronius seemed to believe he was the more capable general and was impatient to prove it.

  Livy suggests Hannibal had full knowledge of the impulsiveness of Sempronius, and Hannibal soon provided Sempronius with an opportunity he could not refuse. The Carthaginians had discovered that some of the local Celts were trying to play both sides, not surprising since the situation was still very fluid. To punish their duplicity and force them to choose, Hannibal sent out a raiding force of around 2,000 infantrymen and 1,000 Celtic and Numidian cavalry to ravage the local territory and take all surplus food from the duplicitous towns, evidently easy pickings. These towns now quickly showed their true colors and publicly went over to the joint Roman camps and requested justice against Hannibal.

  At the news of Punic raids and a Celtic call for retribution, Sempronius practically leaped out of his headquarters. He sent out the bulk of his cavalry and 1,000 javeliners to find the small Carthaginian raiding force laden with booty. His Roman force took more than a few lives and most of the raided goods. The Carthaginians retreated toward the main camp. Hannibal sent out reinforcements to back up the raiding party, which was smaller than the number of troops Sempronius had in the field. In turn, Sempronius sent out the rest of his cavalry and javeliners to contest the Punic reinforcements, who, now fully outnumbered, retreated en masse back to the main camp. Hannibal now commanded this small part of his army to stop its retreat and turn around to face Sempronius, but he forbade his men to attack the Romans.

  Hannibal knew he would lose psychological standing with his Celt allies if his men retreated back to camp without at least appearing to challenge the Romans to come any closer. Facing each other at a visible distance, the two forces had a tense standoff, but when the Romans realized that Hannibal would not fight, they turned and went back to their camp.

  Sempronius believed that this had been a decisive test, especially since more Carthaginians than Romans had died in this small skirmish. Sempronius was all the more fired up to have a full battle with Hannibal even though Scipio had warned him to be cautious, claiming that his new recruits needed training and drills through the winter to be more prepared. While Scipio also wanted to wait until he was fully recuperated, he also argued reasonably that the Celts’ loyalties were as liquid as water, and they would not stay with Hannibal if they had to remain inactive for too long. But his sound advice fell on deaf ears.

  Sempronius urged his fellow consul and also, as Livy puts it, “passionately harangued the officers.” Livy says that Sempronius may have even mocked Scipio’s procrastination: “Were they waiting for a third consul and another army?”11 Sempronius may have hoped that without the still healing Scipio, the glory of a Roman victory would be completely his!

  Hannibal realized that the Celts were fickle and could easily drift away given too much time or not enough victories to keep their morale high. Worse, the Celts could defect to the Romans in enough numbers to reduce his allied forces considerably, or they might pull out altogether, especially when Celt tribes were fighting against Celt tribes in both armies. With his forces trimmed drastically by the ordeal in the Alps, Hannibal needed the Celts more than the Romans did. Hannibal also hoped to keep Scipio out of the battle, preferring to prey on the untested Roman recruits led by Sempronius.

  Thus, while Hannibal would have agreed with Scipio on several points of strategy, he knew it was to his advantage to fight quickly in an enemy land—moving as often as possible12—before Rome could field an even larger army. He knew he needed rapidly but prudently to set up battle conditions that would be favorable to him.1
3 Hannibal wanted the fight on his terms, as would any general in enemy territory. He also wanted his allies confident of success—Polybius states exactly this.14 He knew both his own resources and those of his enemy, thanks to his Celtic sources of intelligence in the Roman camp.

  RECONNOITERING THE BATTLE SITE

  In the near month he had been encamped in the Trebia River Valley, Hannibal had observed a flat, treeless plain on the west side of the river, roughly between the Punic and Roman camps, with an unobstructed view except at the river itself, where reeds and bushes provided good cover on the steep banks. Hannibal knew that he could hide ambush forces near the steep banks, stealth forces the Romans wouldn’t notice because they would be beguiled by the wide-open spaces. He also knew that the wide, flat area would give his superior Numidian cavalry room to maneuver in battle.

  Even now the Trebia River banks often reach a height of fifteen to twenty feet in many places, presumably a deeper river channel than in 218 after two millennia of erosion. But even if only half that height prior to modern farming in the region, many portions of Trebia brush-filled banks would have been sufficient to hide ambush forces.15 Trees would not have been a factor because it was December, and the deciduous leaves would have been gone.

  Hannibal devised a plan that would take advantage of this place and the Roman desire to fight on open plains. Hannibal then confided in his younger brother Mago, bringing him entirely into his devious strategy to trap the Romans. Together they chose two hundred of the toughest veteran leaders: a hundred cavalry and a hundred infantry who were to meet him that night in the camp.

  When these veterans arrived to meet with him, Hannibal asked each to choose ten of the bravest soldiers he knew. When the force of two thousand was collected—a thousand cavalry and a thousand infantry—he sent them out secretly in the middle of the night to a protected ambush spot that was concealed from the Romans. Hannibal may have already done reconnaissance on this very ambush place. No wonder he chose the hardiest and bravest leaders and warriors, because they would have to sit out the cold night outdoors! Hannibal also instructed Mago in the prearranged signals for what to do the next day. If all went as planned, Hannibal could tell Mago when to leave his ambush site; if not, Hannibal may have had scouts and buglers hidden in the intermittent woods between his forces and the ambush site to relay any messages or changes of plan. Timing was especially critical, and Hannibal could not let poor communication ruin such careful planning.

  BAITING THE ROMAN TRAP

  The brilliance of Hannibal’s strategy stands out. Hannibal made sure that his army went to bed early and was thoroughly rested. They arose just before dawn and ate well to strengthen themselves, also covering themselves with grease and fat to insulate themselves from the cold because it was intermittently raining and possibly sleeting. They may have also oiled or greased their horses against the bitter cold. His primary plan was to draw out the Romans, so after he explained his tactics and promised each man rewards, he then sent his mobile Numidian cavalry across the Trebia at daybreak. Their orders were to ride as quickly as possible to the Roman position and shoot as many arrows as needed into the Roman camp, probably accompanied with taunts, hoping to draw out Sempronius and his army before they had eaten. How Hannibal knew Sempronius would take the bait is astonishing. But what followed was even better planning on Hannibal’s part.

  Hannibal seemed to have chosen this day to engage in battle because he knew that in the Roman system, generals alternated command every other day. Hannibal must have known it was Sempronius’ turn to lead. Scipio may have warned him against fighting that day and that it was a bad idea, especially with the foul weather all night that had made the ground either wet or half frozen, but Sempronius didn’t listen to Scipio, thinking only of glory and vastly underestimating Hannibal. Sempronius foolishly did exactly what Hannibal wanted.

  Having crossed the Trebia River, the nimble Numidians rushed the Roman camp with loud taunting as they wheeled their horses about. Sempronius gave the order for his several thousand heavy cavalry to engage these Numidians. Then he dispatched six thousand javeliners and followed them with mobilizing his whole army. He thought rashly that if the enemy cavalry merely saw his numerical superiority, the issue would be decided quickly by overwhelming force. But Sempronius ordered almost all his men to battle without breakfast and ill prepared for the bitter cold and now falling snow, just as Hannibal had hoped.

  Driven by Sempronius’ swaggering expectations, and confident in their heavy armor and numerical superiority, the Romans roared their approval as they poured out to battle. But the Roman heavy cavalry could not keep up with the fleet Numidian light cavalry that wheeled around them, trained for this purpose. Behind them, the Roman infantry could not keep up either, but the men could still hear the Numidians mocking them as they rode ever forward just out of range of weapons.

  Consistently, the darting Numidians lured the Roman army north. The Romans were probably marching as fast and orderly as they could in the cold, bad weather in three columns,16 at least three or so miles along the east Trebia bank. The Numidians knew exactly where to turn west to cross the river ahead of the slow Roman army. Ahead of the infantry, the Roman cavalry began to cross, and the mass of the Roman infantry maniples (subdivisions of sixty to a hundred soldiers) hit the river banks long after the Numidians had crossed. At first, the Numidians waited safely on the other side. As the Roman cavalry crossed, the Numidians darted to the sides, continuing their provocative taunting. The Roman army charged into the river by sheer momentum, fragmenting its organization in the surging water.

  TREBIA RIVER AS A WEAPON

  It is possible that after Hannibal’s army had experienced the debilitating effects of the cold and snowy Alps, he realized the advantage he would gain by forcing a similar experience on the Romans. If weeks of bitter cold and gnawing hunger had reduced his troops to half strength, what could an icy winter day do to the Romans? At the same time, he probably told his men that they had already endured and survived far worse conditions, and this wintry battle would be mild in comparison.

  Here is where the second phase of Hannibal’s plan took force. Since it had rained and sleeted a lot the night before, the river was running higher than usual. When his Numidian cavalry had crossed the Trebia, its oiled horses bore the brunt of the freezing water; the horsemen rode higher, mostly out of the water. But the huge mass of Roman infantry of almost sixteen thousand soldiers and twenty thousand allies struggled up to their chests in the freezing water that surged around them. The Numidian cavalry took off with the heavier Roman cavalry in futile pursuit. The Roman infantry could hardly follow, sodden with cold water and probably freezing as they tried to move. The icing of their clothing slowed them down immensely and also began to rob them of body heat, but they couldn’t stop now. Nor could they turn around to ford the freezing water a second time. After their officers reformed the ranks, the Roman army labored forward.

  Everything was going exactly according to Hannibal’s plans so far.

  BATTLING MORE THAN MEN: WEATHER AND HYPOTHERMIA TOO

  Hannibal had been waiting and took action when he saw the entire Roman army, advancing “at a slow step,” as Polybius notes,17 up the slope of the plain. The Roman infantry was probably sluggish by now, having to march uphill as well. Hannibal first sent out his grease-protected pikemen and Balearic slingers—about eight thousand together, as they always worked jointly. Hannibal’s army advanced about three-quarters of a mile. Then he ordered forward his heavy infantry, totaling twenty thousand allies from Spain, Africa, and Celtic lands in a single line. He put his cavalry on the flanks, about ten thousand, including Celtic allied horsemen, far more than the Romans had mustered because they relied so much on infantry. Hannibal then placed his thirty-seven or so elephants—the strongest of these by now having mostly recovered after a month of rest—in front of his cavalry wings to provide additional protection.

  Sempronius finally recalled his heavy cavalry when he
realized that they could not keep pace with the Numidians. This was a fatal mistake because it left his flanks exposed. With his freezing ranks in some sort of order, Sempronius tried to march his legions forward slowly, hoping to terrorize the motley Punic forces merely by showing up. But it didn’t work. The Roman army was exhausted from cold, heavy frozen clothes and famished with hunger even before the battle.

  When the opposing lines met and combat started, many thousands in the Roman army hardly had sufficient battle strength left. The Roman javeliners had lost most of their projectiles against the elusive Numidians and were also affected by the persistent dampness. Sempronius seemed unaware of the doom awaiting his legions.

  Hannibal’s men were well fed and relatively warm, having moved only enough to stay warm while the Romans had been duped to travel in terrible circumstances. The larger Carthaginian cavalry moved on the Roman flanks and then turned inward, squeezing the sides of the massed Roman infantry, who were unprotected because their cavalry had fallen back. The Carthaginian pikemen joined by the Numidians crushed forward against the massed Roman infantry, who could go nowhere but forward.

  MAGO’S AMBUSH SPRUNG

  Suddenly Mago’s combined forces of infantry and Numidian cavalry appeared from the rear, having left their ambush site. This caused great alarm and confusion among the Romans, but they mostly held their ground. Mago’s smaller force mercilessly attacked the infantry rearguard, which turned to face it while being butchered.