In the Irish saga, Cath Maige Mucrama, Achtan is named as the daughter of Olc Acha of the Crich Óic Bethra, near what is now Clarenbridge, County Galway.
The night before the Battle of Mag Mucrama, Art mac Cuinn he was a guest of Olc Acha, who asked him how many children he had.
To ensure the survival of his bloodline in case of his death, Olc Acha proposed Art sleep with Achtan and conceive a son.
Families descended from these dynasties include MacDermot, O'Conor, Ó Cléirigh, O'Flaherty, O'Dowd, O'Shaughnessy, McGivergan and O Hynes.
The Connachta, after whom the province is named, were said to have been the descendants of Conn Cétchathach, who is supposed to have lived several centuries later.