In the centre was stationed the infantry in unusually deep files, under the command of the consul of the previous year Gnaeus Servilius.

Opposite to this centre Hannibal arranged his infantry in the form of a crescent, so that the Celtic and Iberian troops in their national armour formed the advanced centre, and the Libyans, armed after the Roman fashion, formed the drawn-back wings on either side.

On the side next the river the whole heavy cavalry under Hasdrubal was stationed, on the side towards the plain the light Numidian horse.
After a short skirmish between the light troops the whole line was soon engaged.

Where the light cavalry of the Carthaginians fought against the heavy cavalry of Varro, the conflict was prolonged, amidst constant charges of the Numidians, without decisive result.
In the centre, on the other hand, the legions completely overthrew the Spanish and Gallic troops that first encountered them; eagerly the victors pressed on and followed up their advantage.

But meanwhile, on the right wing, fortune had turned against the Romans.