He tried to increase his small territory by profiting from the war of Rhodes against Byzantium (220) and fought against Attalos I when he sided with Phrygia (207). Ally of Philip V of Macedonia he was party to the peace of Phoinikê, the Romans suppored the kingdom of Pergamon against him. After the treaty of Apamia he welcomed the fugitive Hannibal, who helped him to fight against Eumenês II, However Rome sends Flamininus to demand Hannibal is handed over: the Carthaginian preferred suicide (183). Prusias died shortly thereafter.