<P> The war began with the Carthaginian general Hannibal 's conquest and destruction of the Roman - allied Iberian city of Saguntum in 219 BC , prompting a Roman declaration of war on Carthage in 218 . Hannibal surprised the Romans by marching his army overland from Iberia to cross the Alps and invade Roman Italy , followed by his reinforcement by Gallic allies and crushing victories over Roman armies at Trebia river in 218 and on the shores of Lake Trasimene in 217 . Moving to southern Italy in 216 , Hannibal at Cannae annihilated the largest army the Romans had ever assembled , killing or capturing more than 67,000 Roman soldiers . After the death or imprisonment of 130,000 Roman troops in two years , 40 % of Rome 's Italian allies defected to Carthage , giving her control over most of southern Italy . Macedon and Syracuse joined the Carthaginian side after Cannae and the conflict spread to Greece and Sicily . The Carthaginian navy was built up in the early years of the war and from 215 -- 210 , the Carthaginian army and navy launched amphibious assaults to capture Roman Sicily and Sardinia but were ultimately repulsed . </P>
<P> The war began with the Carthaginian general Hannibal 's conquest and destruction of the Roman - allied Iberian city of Saguntum in 219 BC , prompting a Roman declaration of war on Carthage in 218 . Hannibal surprised the Romans by marching his army overland from Iberia to cross the Alps and invade Roman Italy , followed by his reinforcement by Gallic allies and crushing victories over Roman armies at Trebia river in 218 and on the shores of Lake Trasimene in 217 . Moving to southern Italy in 216 , Hannibal at Cannae annihilated the largest army the Romans had ever assembled , killing or capturing more than 67,000 Roman soldiers . After the death or imprisonment of 130,000 Roman troops in two years , 40 % of Rome 's Italian allies defected to Carthage , giving her control over most of southern Italy . Macedon and Syracuse joined the Carthaginian side after Cannae and the conflict spread to Greece and Sicily . The Carthaginian navy was built up in the early years of the war and from 215 -- 210 , the Carthaginian army and navy launched amphibious assaults to capture Roman Sicily and Sardinia but were ultimately repulsed . </P>
who led the carthaginian army in the second punic war
who led the carthaginian army in the second punic war
Hannibal
Hannibal