In the fifth century these Greek cities in Sicily and Italy were at the height of their power and prosperity. In Sicily they had penetrated from the coast far into the interior where they had brought the Sicels under their domination. By the victory of Himera, in 480 B. C., Gelon of Syracuse secured the Sicilian Greeks in the possession of the greater part of the island and freed them from all danger of Carthaginian invasion for over seventy years. Six years later, his brother and successor, Hieron, in a naval battle off Cyme, struck a crushing blow at the Etruscan naval power and delivered the mainland Greeks from all fear of Etruscan aggression. The extreme southwestern projection of the Italian peninsula had passed completely under Greek control, but north as far as Posidonia and east to Tarentum their territory did not extend far from the seaboard. In these areas they had occupied the territory of the Itali and Oenotrians, while on the north of the Bay of Naples Cyme, Dicaearchia, and Neapolis (Naples) were established in the land of the Opici (Osci). The name Great Greece, given by the Hellenes to South Italy, shows how firmly they were established there. *Lack of political unity.* However, the Greeks possessed even less political cohesion than did the Etruscans. Each colony was itself a city-state, a sovereign independent community, owning no political allegiance to its mother city. Thus New Greece reproduced all the political characteristics of the Old. Only occasionally, in times of extreme peril, did even a part of the Greek cities lay aside their mutual jealousies and unite their forces in the common cause. Such larger political structures as the tyrants of Syracuse built up by the subjugation of other cities were purely ephemeral, barely outliving their founders. The individual cities also were greatly weakened by incessant factional strife within their walls. The result of this disunion was to restrict the Greek expansion and, eventually, to pave the way for the conquest of the western Greeks by the Italian “barbarians.”