A larger Roman offensive, of which it was a part, aimed to subjugate and to punish cities and tribes that had abandoned the alliance with Rome after the Battle of Cannae, and to narrow the base of the Carthaginian leader, Hannibal, in southern Italy.

As neither side gained a decisive victory and both suffered considerable losses (up to 14,000 killed overall[1][2]), the outcome of this engagement was open to differing interpretations by both ancient and modern historians.

While Marcellus took a heavy blow at Canusium, he nevertheless checked for some time the movements of the main Punic forces and thus contributed to the simultaneous Roman successes against Hannibal's allies in Magna Graecia and Lucania.

The loss of the Numidian contingent in Salapia had deprived him of one of his advantages over the Romans – his strong cavalry,[7] so the open and flat terrain was no longer as favorable as it had been at the time of Cannae.

At first they produced the desired effect by trampling and scattering the Roman front, but a successful counterstrike by a maniple of hastati turned the beasts against their own troops and caused disorder among the Carthaginian ranks.

The toll on Marcellus' troops was even heavier than that of the preceding day – 3,000 killed and nearly all the rest wounded, according to Plutarch – so he declined to pursue Hannibal when the latter broke camp and marched south the following night.

Sparing his soldiers, most of whom were wounded, the proconsul retired to Sinuesa (Campania) according to Plutarch, or Venusia (Apulia) according to Livy, where he was inactive the rest of the summer, allowing Hannibal to traverse southern Italy unchecked.

Having disentangled himself from Marcellus, although the army of Fabius was very close to Tarentum, Hannibal hurried to rescue the city of Caulonia (in the farthest corner of southwestern Italy for Bruttium was also under Roman attack).

Unopposed by the main Roman forces the Carthaginian commander managed to intercept and destroy near Caulonia an 8,000 strong detachment that had attacked the Bruttians from Regium,[5][10] and thus retained control over the region.