Alcmene
Ἀλκμήνη
The woman deceived by Zeus in her husband's form, who bore Heracles.
She was the granddaughter of Perseus and the wife of Amphitryon.
According to Apollodorus, Zeus came to her in the form of Amphitryon, away at war — and stretched that one night to three times its length. The next day, her real husband returned.
So twins were born: Heracles, son of Zeus, and Iphicles, son of Amphitryon — one womb, two fathers.
SourcesApollodorus, Library