Orithyia was the daughter of Marpesia. Upon the death of her mother, Orithyia became the new queen of the Amazons. She co-ruled with Antiope, who some authorities say was her sister. She was famous for her perpetual virginity. Her war techniques were oustanding and brought much honor to the Amazon empire.
Sometimes, Hippolyta's role in the labors of Heracles is replaced with Orithyia. King Eurystheus commanded Heracles to go and get the belt from Orithyia, which he thought would be impossible. Heracles gathered nine warships and occupied the shores of the Amazons while Orithyia was away. Because of the confusion and carelessness of the Amazons, their numbers were greatly reduced. Heracles was easily able to capture Melanippe and Hippolyta, Antiope's sisters. Heracles returned Melanippe after getting the queen's girdle, however, Hippolyta was taken away by Theseus, king of Athens, as his share of the spoil. Orithyia then led the Attic War to free Hippolyta and take revenge for the defeat of Antiope. She asked Sagillus, the Scythian king, for assistance, and he sent his son Panasagoras with a body of cavalry to her aid. However, some disagreements occuried between the allies and the Scythians left the battlefield. The Amazons were eventually defeated, but managed to escape to their allies' camp and, under their protection, returned home safely.
Some Thrakian and Scythian slaves were kept in Athens for personally guarding the Athenian king and Orithyia took advantage of this opportunity to avenge her sister's defeat. She summoned the Scythian allies along with the Thrakian allies and sent two sets of diplomatic envoys to negotiate. One set was to contact the slave leaders to gain their assistance for freedom in return and another set to ensure Lakonia did not assist Athens. Orithyia then triumphantly marched her army across the Kimmerian Bosporus over the Danube River and through the area of Thrake. Orithyia besieged Athens but in the battle, Antiope was killed. Orithyia built a tomb for Antiope after completing a treaty with the Athenians. In the battles, Orithyia had received serious injuries and ultimately died of these. She was buried on the route home by her army.