When did the Greeks establish colonies and where were the colonies located?

The began exporting surplus populations from about 900 CE onwards. Eventually there were about 2000 cities established around the Mediterrana and Black Seas, from today's Spain in the west to Asia Minor in the east.

For example Naples (in Greek nea polis = New City) in Italy was a Greek city, as was Tripoli in Libya (tri polis = three cities), Miletus in Asia Minor.