The Greek Colonies
As the Greeks began to see great prosperity, their population exploded. As a result of this increasing population, the farmers in the city-states where not able to produce enough food to support and feed everyone.
To solve this problem, the city-states began to colonize regions around the Mediterranean Sea. These colonies supplied their parent polis, known as a metropolis, with grain and food, while the metropolis would supply its colony with the supplies that it needed.