How did ancient Greece civilization develop?

Nomads from the east settled in Europe over three thousand years ago - the Latin baranch in Italy and the Greek branch in Greece. The Greek branch - nomadic Ionians, Dorians, etc became dominant and in the 1st Millennium BCE set up city-states by the various tribes which spread out, seized land and settled. Once settled by the 8th C BCE, they had the resources (surplus production of food) to develop culture and what we call civilisation, as opposed to the nomad concentration of gaining food and pillaging settled populations.