Hippolyta was the sister of Penthesilea and daughter of Ares and Otrera. She was the Amazonian queen who possessed a magical girdle she was given by her father, Ares, the god of war. Hippolyta was abducted by Heracles and fell in love with Theseus, eventually providing him with a son. The girdle was a waist gelt that signified her authority as queen of the Amazons. She figures prominently in the myths of both Heracles and Theseus. As such, the stories about her are varied enough that they may actually be about several different characters.
A demigod, Hippolyta was mostly famous for her magical belt (or girdle in some cases), which was given to her by her father, Ares, the god of war. The belt greatly increased Hippolyta's physical strength and prowess in battle, and served as a symbol of her authority as queen. The hero Hercules was sent to retrieve Hippolyta's belt for his ninth labor.
Heracles was received warmly by the queen and her tribe and Hippolyta was more than willing to give him the girdle, possibly because she was impressed by his strength and because he was going to give it to the war priestess Admete, but Hera, who hated Heracles, disguised herself as an Amazon and spread word that Heracles was plotting to kidnap the queen.
The Amazons retaliated and Heracles came to believe that Hippolyta had betrayed him. He raped Hippolyta, then killed her, ripped the girdle from her body, then jumped ship. He also killed Celaeno, another Amazon. Another version says that Hippolyta refused to give up the girdle and declared war on Heracles. In battle, Hippolyta's horse threw her to the ground and Heracles offered her mercy but the proud warrior queen refused to give in. Heracles then bashed her in the head.
Before her death, Hippolyta had a son named Hippolytus by Theseus, king of Athens. His father killed him under the false assumption that Hippolytus assaulted his current wife Phaidra because of Aphrodite who sought to punish both of them for Hippolytus' aromantic asexuality. After being revived by Asclepius' Physician's Cure, Hippolytus joined the Hunters of Artemis.
References:
1.Ford, Michael. Heroes, Gods and Monsters of Ancient Greek Mythology. Andrews UK Limited, 2012.
2.Heuscher, Julius, E. "Theseus and Hippolyta on the Couch." American journal of psychoanalysis 49.4 (1989): 319-327.
3.Jennings, Ken. Greek Mythology. Simon and Schuster, 2014.