When Mycenaean society broke up around 1100 BC, the commercial routes
that had linked mainland Greece with the rest of the Mediterranean
were cut. After a period of prolonged recovery, the Greeks began
settling the shore regions of the Mediterranean and Black seas.
This movement (ca. 750-550 BC) was caused by the
need for living space for a rapidly expanding population and for new
markets. The colonies had access to unrestricted native markets and
were able to supply 
Greece with wheat, meat, dried fish, hides, wool, timber and basic
metals in exchange for mainland finished products, olive oil and
wine.
Trade meant Greeks could import luxury products
from Egypt, the Levant, Asia Minor and elsewhere. By 300 BC Greek
manufactured goods were freely circulating to North Africa,
Spain, the Rhone
valley, the Balkans, and as far east as India. (large
version of map)
