Realising that he could not win a war against the Romans, Pyrrhus accepted a request from the Greek city-states of eastern and southern Sicily to help them against the Carthaginians in western Sicily. He went to Sicily and campaigned there for three years. His allies in southern Italy were aggrieved because he abandoned them. He took over all the Carthaginian domains in Sicily except for the stronghold of Lilybaeum. His siege of this city was unsuccessful. After this he wanted to build a large fleet to invade Carthage's home territory in Africa. He needed to man and equip these ships and to do this he treated the Greek city-states despotically. These cities turned against him. He was forced to return to southern Italy. He fought the Romans at the Battle of Beneventum (275 BC), where he was defeated. He then left Italy and returned to Epirus.