Iphigenia, a daughter of Agamemnon and Clytemnestra, or, according to some authorities, of Theseus and Helena. Agamemnon, having once killed a stag in the grove of Diana, sought to appease the offended goddess by vowing that whatever, most beautiful, was born to him in that year should be sacrificed to her. His daughter Iphigenia chanced to be born within the period specified; but the king from time to time put off the performance of his vow, until the Grecian armament was assembled in the port of Aulis to sail against Troy. The winds proving unpropitious, Cal-chas the seer was consulted, and replied that the sacrifice of the daughter of Agamemnon was indispensable to propitiate the gods. But Agamemnon still.resisted, and only'yielded to the importunities of Menelaus. When Iphigenia was about to be immolated, Diana herself intervened to save her, and bore her in a cloud to Tauris, where Iphigenia became her priestess. Her brother Orestes came thither in order to steal the image of Diana, which was believed to have fallen from heaven, and to transport it to Hellas. Iphigenia recognized him, and aided him in obtaining the desired image, with which they fled to Argos. Iphigenia afterward carried it to Sparta, where she acted as priestess of Diana till her death.