ÆGISTHUS, in Ancient History, was the son of Thyestes by his own daughter Pelopea, who, to conceal her shame, exposed him in the woods. Some say he was taken up by a shepherd, and suckled by a goat; whence he was called Ægisthus. He seduced Clytemnestra, the wife of Agamemnon, and lived with her during the siege of Troy. Afterwards, with her assistance, he slew her husband, and reigned seven years in Mycenæ. He was slain, together with Clytemnestra, by Orestes. Pompey used to call Julius Caesar Ægisthus, on account of his having seduced his wife Mutia, whom he afterwards put away, though he had three children by her.