(Πολύκλεια/Polýkleia). Heroine from the family of the Heraclidae, who received an oracular prediction that the first person to cross the Achelous  would become ruler of the Boeoti, who were at the time living in Thessalia. She asked her brother Aeatus to carry her over the river, broke away shortly before reaching the other bank and was the first to set foot there; her brother then married her to secure power for his family and they had a son, Thessalus (Polyaenus, Strat. 8,44).
G. Radke, s. v. Polykleia (1), RE 21, 1695-1698.