After allowing his men to recruit in the villages of the friendly Insubres, he overcame the Taurini, besieging and taking Turin, and forced the Ligurian and Celtic tribes on the Upper Po to serve in his army. At the Ticinus, a stream which enters the Po near Pavia, he encountered the Romans under Scipio, the father of Scipio Africanus. The cavalry of both armies joined battle, Hannibal's Numidian horse proved their superiority, and Scipio fell back beyond the Po. The Carthaginians crossed the river, and the first great battle of the campaign was fought in the plain of the Trebia. Placing Mago in ambush with 2,000 men, Hannibal enticed the Romans across the stream. His light troops retired before the legionaries, and as Scipio was pressing on to fancied victory he was taken in flank by the terrible Numidian horse, Mago came down in the rear, and the 40,000 men of the consular army were either cut to pieces or scattered in flight. Wintering in the valley of the Po, in the early spring Hannibal crossed the Apennines and pushed through a region of lakes, flooded by the melting of the snow, to Faesulae. The beasts of burden perished in vast numbers amid the morasses; the Gauls, disheartened by the perils of the journey, had to be driven forward by Mago's horsemen, and the general lost an eye. Quitting Faesulae, Hannibal wasted Etruria with fire and sword, and marched toward Rome, leaving behind him two consular armies of 60,000 men. He awaited the consul Flaminius by the Lake Trasimene, where the hills, retiring in a semicircle from the shore, inclose a plain entered by two narrow passes. Concealing the main body of his army amid the hills, he placed his Numidians in ambush at the pass by which the Romans must enter; while he stationed part of his infantry in a conspicuous position near the other defile. The Romans pushed into the valley; the pass in their rear was secured by the Carthaginians who had lain in ambush; Hannibal's men charged from the heights, and the army of Flaminius was annihilated. Six thousand infantry cut their way through the farther pass, but these were overtaken by the horse under Maherbal and forced to yield on the following day.