Phthius (founder of Phthiotis)

In Greek mythology, Phthius was the eponymous ruler of Phthiotis in southern Thessaly.

Family

Phthius was the son of Poseidon and Larisa, daughter of Pelasgus. He was the brother of Achaeus and the younger Pelasgus.
Phthius became the father of Amphictyone who bore to Asterius a son, Dotius. The latter being one of the possible eponyms of Dotium in Thessaly.

Mythology

Phthius together with his brothers, left Achaean Argos with a Pelasgian contingent for Thessaly. They then established a colony on the said country naming it after themselves. The only single source of the accounts of Phthius is recounted by Dionysius of Halicarnassus in his Roman Antiquities about the Pelasgian race's migration.