A hostile encounter with the Hellenes could now no longer be avoided and it seems to have been the danger which threatened the Phœnicians from this side which led their scattered settlements to unite into a single state with Carthage as its centre, or at any rate materially assisted Carthage in her work of unification. Above all it was necessary to drive out the Phœnicians from their newly won position on Corsica. The Phœnicians were aided in their attempt by the Etruscans, who, as bold pirates, had long beforehand made themselves feared by the Greeks, and regarded the Phocæan settlements so near their coasts with no less anxiety than the Phœnicians themselves. The Phocæans could not withstand the attack of the two peoples, who were the most skilful navigators in the western Mediterranean. They were indeed victorious in an open sea fight, but they endured such severe losses that they were obliged to give up Alalia. They next turned to south Italy and established there the colony of Hyele, between Pyxus and Posidonia. Massalia was now isolated and thrown upon its own resources. The distant Mænaca could consequently be maintained no longer, and Carthage won undisputed possession of Tartessus. But within its narrow range of power Massalia victoriously resisted all attacks of the Phœnicians, and the final result was that a sort of dividing line was established between the two cities. Massaliot influence was preponderant north of the promontory of Artemisium (cape of Nao); Carthaginian, south of it, on the east coast of Iberia.
Cyrnus came under Etruscan influence after the withdrawal of the Phocæans. The Etruscans, it appears, had already taken possession of the fertile plain on the lower Vulturnus and had established there a number of settlements, whose centre was at Capua. They now proceeded to attack Hellenic Cumæ (presumably in 524). Here, however, the superior military skill of the Greeks won the victory, and the latter were able to defend the Latin cities, which were friendly to them, from being brought into subjection by the Etruscans. The strength of Cumæ, however, was not sufficient to keep up the unequal fight for long and it was due only to the intervention of the Syracusans that Hellenism maintained itself here until the end of the fifth century.
Nearly contemporaneously with the beginnings of colonisation in the west the Hellenes began to spread toward the north and southeast. The Chalcidians again took the first place. Opposite Eubœa a long peninsula projects from the north into the Ægean Sea, which, on account of the numerous indentations of its coast, as well as the fertility of its soil, invited settlement. A long succession of Grecian colonial towns grew up here, the most of which were founded from Chalcis; hence the name Chalcidice, which the peninsula bore in later times. The Corinthians followed the Chalcidians here, just as they had done in the west. On the narrow isthmus joining the peninsula of Pallene with the main body of Chalcidice they founded the colony of Potidæa (in 600) which remained the most important city of this region until the time of the Peloponnesian War. The original Thracian population maintained itself only on the rugged slopes of Athos.
Further east, in the first half of the seventh century, the Parians took possession of the mountainous island of Thasos, which at that time was still covered with a thick primeval forest. The new settlers soon crossed over to the near-lying mainland, where they established a number of commercial stations, as Œsyma and Galepsus, which had to maintain themselves through long struggles with the warlike Thracian tribes. Opposite Thasos, on the fruitful plain between Nestus and Lake Bistonis, the Clazomenæans founded Abdera in 651, but they could not long maintain themselves against the attacks of the Thracians. Colonists from Teos, who emigrated after the conquest of Ionia by the Persians (545) and took possession of the deserted place, were more successful; Abdera now became the most important city on this whole coast and also took an active part in the intellectual life of the nation.
Lesbos and Tenedos were for a long time the most advanced posts of the Hellenic world toward the northeast. Not until the eighth century do the inhabitants of these islands appear to have succeeded in taking possession of the south of Troas, from the wooded slopes of Ida to the entrance to the Hellespont. None of the numerous settlements founded here, however, became very important. The Lesbians then went further and crossed over to the European shore of the Hellespont, where they built Sestus at the narrowest point of the strait and Alopeconnesus on the northern coast of the Thracian Chersonesus. Ænus, at the mouth of the mighty Hebrus, the principal river of Thrace, was also colonised by Mytileneans. The further expansion of the Greeks on this coast was arrested by the warlike tribes of Thrace.