Achaeans, the earliest branch of the ancient Greeks. They were a Greek-speaking, warlike people who between 2000 and 1700 B.C. migrated into and conquered what eventually became known as the Greek peninsula. The area was then under the cultural influence of the Minoans, whose civilization was centered in Crete. The Achaeans adopted much from Minoan culture in building a new civilization called the Mycenaean, named after one of their principal cities, Mycenae.

Another Greek-speaking people, the barbaric Dorians, swept down from the north about 1100 B.C. Two groups of the Achaeans, the Aeolians and the Ionians, fled. Some took refuge in Attica, others migrated to the Aegean islands and the west coast of Asia Minor. A third group, the Arcadians, were conquered and absorbed by the Dorians.