After the Late Bronze Age the entire Aegean region entered a historical period termed the Greek Dark Ages. Archaeologically it was known as the Proto-geometric and Geometric Periods, which did not belong to any one ethnic group. This is the time to which heavy Ionic migration from mainland Greece to the coast of Ionia and the emergence of Delos as an Ionian center is believed to apply. These events were over at the start of the brilliant renaissance of the Orientalizing Period in which Ionia played a cardinal role.