 The Roman navy had been mobilized in 219 BC, fielding 220 quinqueremes for fighting the Illyrians.Publius Cornelius Scipio received four legions (8,000 Roman and 14,000 allied infantry and 600 Roman and 1,600 allied horse) and was to sail for Iberia escorted by 60 ships.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.