The relationship between Rome and the Latin cities remained ambivalent, and many "socii" rebelled against the alliance whenever the opportunity arose. The best opportunities were provided by the invasion of Italy by the Greek king Pyrrhus from 281 to 275 BC, and by the invasion of Italy by Carthaginian general Hannibal from 218 to 203 BC. During these invasions, many "socii" joined the invaders, mostly Oscan-speakers of southern Italy, most prominently the Samnite tribes, who were Rome's most implacable enemy. At the same time, however, many "socii" remained loyal, motivated primarily by antagonisms with neighbouring rebels. Even after Rome's disaster at the Battle of Cannae (216 BC), over half the "socii" (by population) did not defect and Rome's military alliance was ultimately victorious.