Alcmena, in Greek mythology, a daughter of Electryon, king of Mycenae. She had ten brothers, who, save one, were slain by the sons of Pterelaus. Alemena had been betrothed to Amphitryon, but she nevertheless declared that the man who avenged the death of her brothers should be her husband. Amphitryon, in order to prove himself worthy of her hand, undertook the enterprise. During his absence, Jupiter visited Alemena, and by assuming the likeness of Amphitryon, and pretending to have avenged the death of her brothers, obtained her favor. She thus became the mother of Hercules, almost at the same time that she bore Iphieles to Amphitryon. After her death, Jupiter sent Mercury to transport her body to the Elysian isles.