Iphigenia was the daughter of Agamemnon, king of Mycenae and general in the Greek forces against Troy. Unfavourable winds initially prevented the forces from sailing, so Agamemnon consulted the seer Calchas. He predicted that because Agamemnon had killed a stag sacred to Diana, he would have to sacrifice his own daughter to redeem himself. Iphigenia accepted her fate and was brought to the altar. When the flames were lit, Diana rescued Iphigenia and substituted her with a stag, carrying Iphigenia away to be her priestess. The winds changed and the Greek were able to sail.