In Ancient Greece, colonies are sometimes founded by vanquished people, who leave their homes to escape subjection at the hand of a foreign enemy; sometimes as a sequel to civil disorders, when the losers in internecine battles leave to form a new city elsewhere; sometimes to get rid of surplus population, and thereby to avoid internal convulsions; and sometimes as a result of ostracism.

In most cases, however, the motivation is to establish and facilitate relations of trade with foreign countries and further the wealth of the mother-city (in Greek, metropolis).

Colonies are established in Ionia and Thrace as early as the 8th century BCE.More than thirty Greek city-states have multiple colonies around the Mediterranean world, with the most active being Miletus, with ninety colonies stretching throughout the Mediterranean Sea, from the shores of the Black Sea and Anatolia (modern Turkey) in the east, to the southern coast of the Iberian Peninsula in the west, as well as several colonies on the Libya coast of northern Africa, from the late 9th to the 5th centuries BCE.There are two similar types of colony, one known as an apoikia (pl.

: apoikiai) and the other as an emporion (emporia).

The first type of colony is a city-state on its own; the second is a Greek trading-colony.