However, Gauls of the Boii and Insubre tribes in northern Italy attacked the Roman colonies of Placentia and Cremona, causing the Romans to flee to Mutina, which the Gauls then besieged. Praetor L. Manlius Vulso marched from Ariminium with two Roman legions, 600 Roman Horse, 10,000 allied infantry and 1,000 allied cavalry towards Cisalpine Gaul.
Meanwhile, the Boii and Insubre tribes in northern Italy launched a surprise attack on the Roman colonies of Placentia and Cremona, forcing the Romans to flee to Mutina, where they were subsequently besieged. The Roman general L. Manlius Vulso marched his forces from Ariminium towards Cisalpine Gaul with two legions, 600 Roman Horse, 10,000 allied infantry, and 1,000 allied cavalry.