Migrations from the east brought the foundations of new civilizations to the Greek mainland, the island of Crete, and the Cyclades Islands east of the Peloponnesian Peninsula (more commonly known as the Peloponnesus; Greek form Peloponnisos). The Minoan civilization (in Crete) and the Mycenaean civilization (on the mainland) developed distinctive social structures that are documented in archeological records. The dominant Mycenaean civilization then declined for a 250-year period known as the Dark Age of Greece.

Data as of December 1994