The struggle for control of the straits dividing Sicily from southern Italy brought the two great empires of the Mediterranean, Carthage and Rome, head to head. It was a world in which ruthless mercenaries prospered.
Hiero II, the ruling general of the Greek city-state of Syracuse, led a campaign in 265 BC north towards a coastal Sicilian city, Messana, held by a group of Campanian mercenaries known as the Mamertines. The Campanians were part of a vast Oscan tribal group originally from the Apennine mountains, who had now settled in the southern Italian region of Campania. By the end of the fifth century BC the hill tribes had invaded the nearby plains, displacing the Etruscan and Greek inhabitants of the region, taking control of nearly all of the land between Salerno and Cumae. As the decades passed, the mountain dwellers gradually let go of their old way of life and adopted the civic lifestyle of the people they had conquered. The newly sedentary Campanians appealed to the Romans for their help against their aggressive neighbours, the Samnites. In 343 BC Rome came to their aid and, in turn, the Campanians became subjects of the Republic. From then on the Campanians were considered civites sine suffragio, meaning they had all of the privileges of Roman citizens but without the right to vote in Rome.