After the Etruscan immigration two other great tribes, this time of Aryan descent, pressed southward from the valley of the Po. Of these the first to come were probably the Siculi, a tribe which subsequently spread over Sicily and all the southwestern part of the mainland. The Ausonians of Campania belonged to this race, as did the dwellers in the “lowland” south of the Tiber, _i.e._, in Latium. The last to come was probably the Sabello-Umbrian race, which entered the country from the north by way of the Apennine valleys. For a long while it kept chiefly to the mountainous tracts of middle Italy, though some members of the tribe pushed forward, like advanced posts, to the west coast. The Umbrian settlement north of the Apennines was the only one which grew to large dimensions. If we reflect that, besides these immigrations, a steady stream of Greek colonists had been occupying the coast of southern Italy ever since the eighth century B.C., their first settlements dating from two centuries earlier, and that, since the fifth century B.C. at latest, Gauls had been crossing the Alps to the valley of the Po, we can readily understand that Italy inevitably became the scene of violent conflicts. Yet she did not wholly miss the salutary effects of peaceful rivalry between the various racial elements. The population of southern Italy adopted the language, manners, and customs of the Greeks, and in the north the Etruscans served both as exponents of their own peculiar civilisation and as intermediaries between the Greeks and the mountain tribes.