"Hasdrubal had led his close order cavalry in a devastatingly brutal charge against the Roman right wing, shattering and virtually destroying it in a brief pursuit. The Carthaginian had kept his men under tight control and, when they had rested and reformed, he led them behind the Roman main line, moving against Varro on the left, and ignoring the massed infantry in the enemy centre. Varro's allied horsemen were still engaged in their stand-off with the Numidians, but the sight of the lines of Hasdrubal's Gauls and Spaniards approaching from the rear utterly shattered their spirit. Without waiting for the Carthaginians to charge home, the Roman left wing dissolved into a panicked flight in which the consul joined. Their position was untenable, and, if they had in fact formed with their flank on the hills around Cannae, any delay in flight might have resulted in their being trapped. They could not have won any combat with a more numerous enemy attacking from two sides, but their flight sealed the fate of the Roman army."