After Cannae, Hannibal needed a maritime base to allow reinforcements and supplies to reach him. But he failed to win over or capture Naples, an old Roman naval ally, and had mixed results elsewhere in Campania: he was successful at proud Capua. He was under-supported from Carthage for all his time in Italy, whether because they could not or would not help him. In 215, he signed a treaty of alliance with Philip V of Macedon. This brought few benefits to either party and would long be remembered by the Romans. Syracuse in Sicily went over to Hannibal in 214 but was recaptured by Claudius Marcellus (late 212). Similarly most of coastal Tarentum in south Italy was in his hands, but only between 212 and 209. In 211, when Capua was under Roman pressure, Hannibal marched on Rome as a diversionary tactic but soon withdrew. Capua fell and was harshly treated.