Iphigenia was the daughter of Agamemnon and Clytemnestra in Greek mythology.
While the Greek army was preparing to set sail for Troy during the Trojan War, Agamemnon caused the anger of the goddess Artemis, because he killed a sacred deer. So, she decided to stop all winds, and the ships would not be able to sail. The seer Calchas realised what the problem was, and informed Agamemnon that to appease the goddess, Agamemnon had to sacrifice Iphigenia to her. Reluctant at first, Agamemnon was forced to agree in the end. He lied to his daughter and his wife by saying that Iphigenia was to marry Achillles before they left. The mother and daughter happily went to the port of Aulis, only to find out the horrible truth. Achilles, unaware that his name was used in a lie, tried to prevent the sacrifice, but Iphigenia utterly decided to sacrifice herself in honour and of her own volition. The most popular version of what happened afterwards is that on the moment of the sacrifice, the goddess Artemis substituted Iphigenia for a deer, but Calchas who was the only witness remained silent. Iphigenia was then brought by Artemis to the city of Tauris where she became the goddess' priestess.
Years later, after Orestes, Iphigenia's brother, had killed his mother and her lover Aegisthus, he was hunted by the Erinyes for committing matricide. He was then advised to go to Tauris, take the carved wooden image of Artemis and bring it back to Athens. In Tauris, where he went with his friend Pylades, he was taken captive by the locals, and the two men were brought before Iphigenia. Although initially the two siblings did not recognise each other, they finally realised the truth and managed to escape the city. They then returned to Greece, where Iphigenia continued to serve Artemis as a priestess in her temple.
See Also: Agamemnon, Clytemnestra, Trojan War, Orestes, Calchas, Artemis, Aegisthus