The first traces of settlement in Patras date to the 3rd millennium BC, in modern Aroe. During the Middle Helladic period (the first half of the 2nd millennium BC) another settlement was founded in the region. Patras flourished for the first time during the Post-Helladic or Mycenean period (1580–1100 BC).
Ancient Patras was formed by the unification of three Mycenaean villages located in modern Aroe, Antheia and Mesatis. The foundation of Patras goes back to prehistoric times, the legendary account being that Eumelus, having being taught by Triptolemus how to grow grain in the rich soil of the Glaucus valley, established three townships, Aroe (i.e. “ploughland”), Antheia (“the flowery”), and Mesatis (“the middle settlement”) united by the common worship of Artemis Triclaria at her shrine on the river Meilichus.