The Carthaginians captured the chief city of the hostile Taurini (in the area of modern Turin) and their army routed the cavalry and light infantry of the Romans at the Battle of Ticinus in late November. As a result, most of the Gallic tribes declared for the Carthaginian cause, and Hannibal's army grew to more than 40,000 men. The Senate had ordered the consul Sempronius Longus to bring his army back from Sicily, where it had been preparing for the invasion of Africa, to join the Roman army already facing Hannibal. The combined Roman force under the command of Sempronius was lured into combat by Hannibal on ground of his choosing at the Battle of the Trebia. The Carthaginians encircled the Romans and only 10,000 out of 42,000 were able to fight their way to safety. Having secured his position in northern Italy by this victory, Hannibal quartered his troops for the winter among the Gauls. The latter joined his army in large numbers, bringing it up to 60,000 men.