The battle of the Trebia was the first major battle of the Second Punic War, fought between the Carthaginian forces of Hannibal and a Roman army under Sempronius Longus on 22 or 23 December 218 BC near modern Piacenza in northern Italy. Each army had a strength of about 40,000 men; the Romans were stronger in infantry, while the Carthaginians were stronger in cavalry and fielded about 30 war elephants (statuette pictured). Hannibal used his Numidian cavalry to lure the Romans out of their camp and onto ground of his choosing. Fresh Carthaginian cavalry routed the outnumbered Roman cavalry, and Carthaginian light infantry outflanked the Roman infantry. A previously hidden Carthaginian force attacked the Roman infantry in the rear. Most of the Roman units then collapsed and most Romans were killed or captured, but 10,000 under Sempronius maintained formation, fought their way out and reached the safety of Piacenza. The following spring the Carthaginians moved south into Roman Italy and operated there for 15 years. (Full article...)