Pre-Crisis, Astarte was thought to be an alien warrior. She traveled in her Silver Snake across the universe, searching for a specific person. That person turned out to be Wonder Woman, and when she encountered the Amazon, she immediately attacked. Somehow, Astarte thought she had some claim to Wonder Woman's body, and it had become possessed by some evil. However, after witnessing Wonder Woman's heroic deeds, Astarte realized she was wrong and apparently killed herself.
Wonder Woman, confused by the situation, had her mother Hippolyte inspect the remains of Astarte. Hippolyte's appearance triggered Astarte's return, and she attacked the group of Amazons in outer space. Hippolyte eventually realized that Astarte was the spirit of Diana, Hippolyte's sister, who had been killed by Hercules before the Amazons founded Paradise Island. Wonder Woman's body was modeled in Diana's image, which led Astarte to think it was her own body, now possessed by evil. Astarte, shocked by this revelation, left her golden body and joined Athena and Aphrodite in the afterlife.
The second woman to call herself Astarte was an Amazon woman who was kidnapped and driven insane by an alien race called The Citizenry. Astarte would become their leader and supervised scientific endeavors into radical gene modification that were used on themselves to become super-humun warriors. One of the test subjects was Astarte's daughter Theana.
This super warriors then would attack planets and steal their natural resources.