Battle of the Trebia

In December 218 BCE, Hannibal fought his first major engagement in Italy during the Second Punic War. Exploiting the rash temperament of Roman consul Sempronius Longus, Hannibal lured Roman forces across the freezing Trebia River at dawn. His soldiers, rested and prepared for the cold, faced shivering Romans who had forded the icy water. A concealed force of 2,000 under Hannibal's brother Mago struck the Roman rear. At least 15,000 Romans died and thousands more were captured. The victory persuaded many Gallic tribes in northern Italy to join Carthage.