An Egyptian divinity, the wife and sister of Osiris and mother of Horus, the three together forming a trinity, which is characteristically Egyptian, and such as often repeats itself in Egyptian mythology, and typifying the life of the sun, Osiris representing that luminary slain at night and sorrowed over by his sister Isis, reviving in the morning in his son Horus, and wedded anew to his sister Isis as his wife; passed into the mythology of the Greeks, Isis became identified first with Demeter and then with the Moon, while in that of Rome she figures as the Universe-mother.