In Greek mythology, Thasus or Thasos ( or ; Ancient Greek: Θάσος) was a son of Poseidon (or, in other versions, Agenor, Phoenix or Cilix ). In the stories, he was a Phoenician prince and one of those who set out from Phoenicia in search of Europa (Thasus' sister ). His brother, Cadmus, gave him a part of the army and left him on an island (i.e. Thasos) where he "founded" the eponymous town of Thasos.