More than thirty Greek city-states had multiple colonies around the Mediterranean world with ninety colonies stretching throughout the Mediterranean Sea. These colonies stretched from the shores of the Black Sea 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. Two flushes of new colonists set out from Greece at the transition between the Dark Ages" and the start of the Archaic Period, one in the early 8th century BC and a second burst of the colonizing spirit in the 6th century. Population growth and cramped spaces at home seem an insufficient explanation, while the economical and political dynamics produced by the competitive spirit between the frequently kingless, newly introduced concept of the Greek city-states, striving to expand their sphere of economical influence better fits as their true incentive."