Circumstances
Roman consuls Publius Scipio and Sempronius had united both their city’s legions near the river Trebbia. This gave them a large force, but their troops were only half-trained, and Scipio’s men suffered from low morale. Scipio was a very capable general – unfortunately, a wound he’d taken at the Ticinius placed Sempronius in charge. Sempronius was inexperienced, impulsive, and glory-hungry.A
Hannibal led a much smaller force of men who were still fatigued from crossing the Alps, but rich in combat experience. He also had an overwhelming advantage in cavalry. His spies had informed him of Scipio’s condition, as well as Sempronius’ incompetence and aggressive nature.
Tactics and Outcome
Scipio insisted the Roman army should avoid battle, and spend the winter training; Sempronius ignored him, and soon made camp near Hannibal’s main force. His exact plans are unknown – after setting up camp, he did nothing but react predictably to Hannibal’s moves.
Hannibal’s plan centered on the river Trebbia, which ran through the open ground between the opposing camps and possessed steep, overgrown banks. The night before he provoked the battle, he hid 2,000 infantry and cavalry along these banks at a point where the Roman army would not see them as it crossed.
The next morning, Hannibal sent his light cavalry to raid the Roman camp before the troops within had time to eat breakfast; meanwhile the main body of Carthaginian troops ate, armed, and prepared themselves for cold-weather battle at each man’s leisure.
Hannibal’s light cavalry harassed the Roman camp until, against Scipio’s protests, Sempronius deployed his entire force and marched against the Carthaginians, who by now awaited him with their main force on the opposite bank of the Trebbia. In order to reach the battlefield, the ill-prepared Romans endured a lengthy march through the cold and then waded chest-deep through the frigid river; many of their soldiers and horses likely found themselves in the grip of hypothermia before the battle began.B
Given the circumstances Hannibal created, the ensuing fight went predictably. Both armies drew up in the standard fashion for the time: infantry in the center and horsemen on the flanks, except for the Carthaginian ambush party waiting in the Roman rear. Hannibal’s elephants marched with his cavalry.
The outnumbered Roman cavalry broke soon after first blood was shed, and Hannibal’s cavalry then attacked the flanks of the Roman center.
Hannibal’s 2,000 who lay hidden along the riverbank then emerged and attacked the Roman infantry from behind, which threw it into disorder. General slaughter of Rome’s infantry ensued; aside from 10,000 of her heavies who cut their way out of the ambush, few survived. Those who escaped fled to the nearby city of Placentia, along with the cavalry.
A. Livy elaborates on Sempronius, accusing him of even worse contempt for Scipio and overconfidence in himself than one might assume from his performance.
B. Livy mentions Roman soldiers shivering and losing motor control in their hands.
Sources
1. Polybius. The Rise of the Roman Empire. Translation by Scott-Kilvert, Ian. New York: Penguin Group, 1979. Penguin Press, Inc., New York 10014.
2.Cottrell, Leonard. Hannibal: Enemy of Rome. New York: Da Capo Press, 1992. Da Capo Press Inc, New York 10013.
*3. Livy. The War with Hannibal. Translation by De Selincourt, Aubrey. New York: Penguin Group, 1965. Penguin Press, Inc., New York 10014.
*primarily for fact-checking. In-text citations were omitted because Cottrell and Polybius closely agreed on everything.
