In northern Italy only the coast of Liguria is occupied by the Mediterranean race. In the valley of the Po the Mediterraneans predominated during the early Neolithic but with the introduction of bronze the Alpines appear and round skulls to this day prevail north of the Apennines. About 1100 B. C. the Nordic Umbrians and Oscans swept over the Alps from the northeast, conquered northern Italy and introduced their Aryan speech, which gradually spread southward. The Umbrian state was afterward overwhelmed by the Tyrrhenians or Etruscans, who were of Mediterranean race and who, by 800 B. C. had extended their empire northward to the Alps and temporarily checked the advance of the Nordics. In the sixth century B. C. new swarms of Nordics, coming this time from Gaul and speaking Celtic dialects, seized the valley of the Po and in 382 B. C. these Gauls, heavily reinforced from the north and under the leadership of Brennus, stormed Rome and completely destroyed the Etruscan power. From that time onward the valley of the Po became known as Cisalpine Gaul. Mixed with other Nordic elements, chiefly Gothic and Lombard, this population persists to this day, and is the backbone of modern Italy. A continuation of this movement of these Gauls, or Galatians as the Greek world called them, starting from northern Italy occurred a century later when these Nordics suddenly appeared before Delphi in Greece in 279 B. C. and then crossed into Asia Minor and founded the state called Galatia, which endured until Christian times. South Italy until its conquest by Rome was Magna Græcia and the population to-day retains many Pelasgian Greek elements. It is among these classic remnants that artists search for the handsomest specimens of the Mediterranean race. In Sicily also the race is purely Mediterranean in spite of the admixture of types coming from the neighboring coasts of Tunis. These intrusive elements, however, were all of kindred race. Traces of Alpines in these regions and on the adjoining African coast are very scarce and wherever found may be referred to the final wave of round skull invasion which introduced bronze into Europe. In Greece the Mediterranean Pelasgians speaking a Non-Aryan tongue were conquered by the Nordic Achæans, who entered from the northeast according to tradition prior to 1250 B. C. probably between 1400 and 1300 B. C. Doubtless there were still earlier waves of these same Nordic invaders as far back as 1700 B. C., which was a period of general unrest and migration throughout the ancient world. The Nordic Achæans and Mediterranean Pelasgians as yet unmixed stand out in clear contrast in the Homeric account of the ten year siege of Troy, which is generally assigned to the date of 1194 to 1184 B. C. The same invasion that brought the Achæans into Greece brought a related Nordic people to the coast of Asia Minor, known as Phrygians. Of this race were the Trojan leaders.