With these exceptions, they had been obliged to leave Apulia and the southern districts totally to themselves.
The insurrection spread; when Mutilus advanced into Campania at the head of the Samnite army, the citizens of Nola surrendered to him their city and delivered up the Roman garrison, whose commander was executed by the orders of Mutilus, while the men were distributed through the victorious army.

With the single exception of Nuceria, which adhered firmly to Rome, all Campania as far as Vesuvius was lost to the Romans; Salernum, Stabiae, Pompeii, Herculaneum declared for the insurgents; Mutilus was able to advance into the region to the north of Vesuvius, and to besiege Acerrae with his Samnito-Lucanian army.

The Numidians, who were in great numbers in Caesar's army, began to pass over in troops to Mutilus or rather to Oxyntas, the son of Jugurtha, who on the surrender of Venusia had fallen into the hands of the Samnites and now appeared among their ranks in regal purple; so that Caesar found himself compelled to send home the whole African corps.

Mutilus ventured even to attack the Roman camp; but he was repulsed, and the Samnites, who while retreating were assailed in the rear by the Roman cavalry, left nearly 6000 dead on the field of battle.

It was the first notable success which the Romans gained in this war; the army proclaimed the general -imperator-, and the sunken courage of the capital began to revive.