In 218 BC, the Insubres and the Boii rebelled in anticipation of Hannibal's invasion of Italy in the Second Punic War (218-201 BC). They attacked Cremona and Placentia, forcing the settlers to flee to Mutina, which was besieged. The praetor Lucius Manlius Vulso set off from Ariminum with 20,000 infantry and 1,600 cavalry. He was ambushed twice on the way. He relieved the siege of Mutina, but was in turn besieged nearby. The consul Publius Cornelius Scipio was sent to support him with fresh troops. Meanwhile, Hannibal reached Italy. He defeated Publius Scipio at the Battle of Ticinus, in Insubre territory and the other consul, Tiberius Sempronius Longus, at the Battle of the Trebia, near Placentia.