One of the more unpleasant stories about Agamemnon was that when he had gathered the ships of all the Greek armies at Aulis, ready to sail for Troy, unfavorable winds kept the fleet from departing. Agamemnon had offended the goddess Artemis, and he was told that he could placate the goddess and get favorable winds only if he sacrificed his daughter, Iphigenia. Some variants of the story say he did; some say he didn't. Some say that although he offered Iphigenia as a sacrifice, Artemis took pity and substituted a deer for the girl. Artemis took Iphigenia to Tauris, where she became a priestess. Euripides, a classical Greek playwright, wrote two Iphigenia plays, one about her sacrifice at Aulis, and another about her years in Tauris.
In seventeenth century France, Racine retold the story of Iphigenia at Aulis, modifying the ancient Greek story with neoclassical French sensibility. The Greek army is gathered at Aulis, the winds are unfavorable, Agamemnon is told to sacrifice his daughter. He waffles, saying he will, saying he won't. Ulysses pressures him into doing it, because the army would rebel if he did not. Agamemnon sends a letter to his wife, Clytemnestra, asking her to send Iphigenia to Aulis, where he will marry her to Achilles (who knows nothing of this). Then Agamemnon tries to send another letter, telling them not to come, but it is too late.
Iphigenia arrives and finds out what is in store for her. She is an amazingly dutiful daughter, and is willing to die for her father and the Greek cause. She is taken to be sacrificed, but at the end a messenger comes, saying that she had disappeared from the altar, and been replaced by a deer.