Hannibal achieved some measure of success in eliciting defections from among the Samnites, especially in southern and western Samnium (the lands of the Hirpini and Caudini, respectively). Several communities of the Hirpini came over to Hannibal in the immediate wake of the battle of Cannae. According to Livy (23.1.1–3), Hannibal was invited to Compsa, which then fell into his hands peacefully. After this, Hannibal placed part of his army under the command of Mago, whom ‘he ordered either to receive the cities of this region that were then defecting from the Romans, or to compel those to defect that were refusing to’. The passage clearly illustrates that other Hirpinian communities began to fall away from Rome at about the same time as Compsa. In 215 the Romans reportedly conducted raids against the Hirpini in the vicinity of Nola, obviously against towns that had defected. It is likely that they had rebelled in the previous year. Besides Compsa, the names of only a few rebellious Hirpinian towns are known: Vercellium, Vescellium, Sicilinum, Meles and Marmoreae.

Similarly, we hear of the Romans capturing towns that belonged to the Caudini or laying waste to their territory, indicating that several had defected. M. Claudius Marcellus and Q. Fabius Maximus conducted campaigns in the vicinity of Caudium in 215 and 214, during which the Romans took Compulteria/Conpulteria, Trebula Balliensis, Austicula and Telesia.