A major factor in the tragedy surrounding Herakles was the hatred that the goddess Hera, wife of Zeus, had for him, as he was one of the god’s illegitimate children, born to him by the mortal woman Alkmene. Zeus, lusting after her, took the guise of Alkmene’s husband Amphityron (he had been away fighting a war at the time) and lay with her. The real Amphitryon returned to Thebes later that night, and Alkmene became pregnant with his son, Iphicles. On the night Herakles and his twin Iphicles were slated to be born, Hera made Zeus swear an oath that the next descendant of Perseus to be born would become High King (ruler of Tiryns and Mycenae). Once the oath was made, Hera hurried to Alkmene’s house in Thebes, where Eileithyia, goddess of childbirth, had come to help deliver the twins; Hera arranged for Eileithyia to keep her legs and arms crossed, causing Herakles and his twin to be trapped in the womb. Hera then caused Eurystheus (son of Sthenelus and Herakles’ cousin) to be born prematurely, making him the one to become the High King instead. Alkmene wouldve remained in labor, had it not been for her maidservant Galanthis, who came out of Alkmene's room to announce (falsely) that Alkmene had just given birth. Eileithyia jumped up in surprise, allowing Herakles and his twin to be born. Hera angrily turned Galanthis into a weasel. (Herakles was given the name Alkeides, meaning "of the line of Alcaeus", father of Amphitryon).