The Achaeans were the first of the Greek-speaking peoples who arrived on mainland Greece around 2000 BC. They were the founders of the city of Mycenae, in the north-eastern Peloponnese, that gave its name to the Mycenaean civilisation of Late Bronze Age Greece (1700-1200 BC). There is no consensus regarding their origin. The Hittites knew them as Ahhiyawa. Helike, one of their cities, was destroyed by inundation following an earthquake in a similar manner to the destruction of Atlantis as described by Plato. It was not until 1500 BC that the Achaeans conquered Crete.

Homer referred to the Achaeans as Achaioi as well as Argives and Danai. Achaioi was probably the Anatolian name for them. Argives refers to the inhabitants of Argos and the Danai were the descendants of the Egyptian Danus who moved to Argos. Homer used Danai as a general term applied to all Greeks. Similarly, it quite possible that Atlantis and its inhabitants had a number of different names. 

Some writers such as Jürgen Spanuth^[015] and more recently Felice Vinci^[019] have argued strongly in favour of the controversial theory that the Achaeans were a Baltic tribe that migrated south.