|Hannibal's Route to the Alps|
As he expected, this forced the hand of Carthage and triggered off the series of events that started the Second Punic War.
After his troops had plundered the city and collected booty, Hannibal went into winter quarters and sent his Spanish troops back home with orders to muster at New Carthage in the spring. Meanwhile, he further developed his plans for the invasion of Italy.
He knew that the Roman strength depended on the resources of the Italian confederacy. Thus he conceived the plan of cutting off their source of strength by carrying the war into Italy and causing a disintegration of the league.
Carthage's once-dominant navy had been destroyed following the First Punic War and Rome now controlled the Mediterranean. Thus any seaborne attack on Italy would have probably met with failure before reaching land. He was also aware the Romans, with their supremacy at sea, might invade either Spain and Africa - or both.
Hannibal believed that he could take the Romans off-guard by a surprise attack on Italy through the Alps, although the land route was long and arduous. In fact it was the only way that he could attack and seize the initiative.
Based on information from his spies, he hoped that by marching through southern Gaul, over the Alps and into Italy, he would be able to pick up many Celtic tribes lying along his route as allies. Many of these tribes had been defeated by the Romans in 225 BC and considered Rome an enemy.