Here the consul Quintus Lutatius Catulus was to guard the passes; but not fully acquainted with the country and afraid of having his flank turned, he had not ventured to advance into the Alps themselves, but had posted himself below Trent on the left bank of the Adige, and had secured in any event his retreat to the right bank by the construction of a bridge.

When the Cimbri, however, pushed forward in dense masses from the mountains, a panic seized the Roman army, and legionaries and horsemen ran off, the latter straight for the capital, the former to the nearest height which seemed to afford security.
With great difficulty Catulus brought at least the greater portion of his army by a stratagem back to the river and over the bridge, before the enemy, who commanded the upper course of the Adige and were already floating down trees and beams against the bridge, succeeded in destroying it and thereby cutting off the retreat of the army.
But the general had to leave behind a legion on the other bank, and the cowardly tribune who led it was already disposed to capitulate, when the centurion Gnaeus Petreius of Atina, struck him down and cut his way through the midst of the enemy to the main army on the right bank of the Adige.

Thus the army, and in some degree even the honour of their arms, was saved; but the consequences of the neglect to occupy the passes and of the too hasty retreat were yet very seriously felt Catulus was obliged to withdraw to the right bank of the Po and to leave the whole plain between the Po and the Alps in the power of the Cimbri, so that communication was maintained with Aquileia only by sea.

This took place in the summer of 652, about the same time when the decisive battle between the Teutones and the Romans occurred at Aquae Sextiae.

Had the Cimbri continued their attack without interruption, Rome might have been greatly embarrassed; but on this occasion also they remained faithful to their custom of resting in winter, and all the more, because the rich country, the unwonted quarters under the shelter of a roof, the warm baths, and the new and abundant supplies for eating and drinking invited them to make themselves comfortable for the moment.