Herakles' ninth labour was to obtain the girdle, at the request of Admete, Eurystheus' daughter. In one version of the story, Hippolyte fell in love with Heracles and freely gave him the belt. According to another the girdle is obtained by Herakles kidnapping Hippolyte's sister, Melanippe, and demanding the girdle as the ransom, succeeding and thus releasing the sister.
After Herakles gets the girdle, Theseus, one of Herakles' companions (also including Sthenelus), kidnaps Antiope, another sister of Hippolyte. The Amazons then attack (because Hera, Herakles' enemy, has spread a vicious rumour that Herakles was there to attack them or to kidnap Hippolyte) but Herakles and Theseus escape with the girdle and Antiope. According to one version, Herakles kills Hippolyte as they flee. In order to rescue Antiope, the Amazons attack Athens but fail, in some versions with Antiope dying in the enslaught.
In many versions Theseus marries either Antiope or Hippolyte, having a son Hippolytus. Theseus eventually marries Phaedra, having left his wife, or his wife having died after childbirth. In the version where Theseus is married to, and leaves, Hippolyte, Hippolyte tries to exact revenge by bringing the Amazons into Theseus and Phaedra's wedding to kill everyone, though this fails as she is killed by, in some versions Theseus' men, in others Penthesilea, another Amazon.
When the sun is in the constellation of Aries, the constellation Andromeda sets. Andromeda, having an apparent long skirt, is considered by greek mythology, to be female. It also has three bright close stars forming a line, leading to the impression of a belt (as do the three in Orion). Girdle is just another word for belt.
The full constellation appears to have something long attached to its upper body, in the greek myth of the Boast of Cassiopeia, it is identified as a chain. Other tales identify it as a sword (discarding parts of the chain from being part of the constellation), implying that the constellation is an amazon warrior. The queen of the amazons was given the name Hippolyte in greek mythology.
Heading in the direction of the sun's transit moves next after Andromeda to the Pleiades, considered in Greek mythology to be the seven sisters. After Herakles obtained the girdle of Hippolyte, he had to face a band of women (more amazons).