Alcmene was the most beautiful mortal woman born to Electryon, king of Tiryns and Mycenae in Argolis. Her mother was either Anaxo or Lysidice according to ancient accounts, though some versions claimed she was the daughter of Amphiaraus.
Zeus disguised himself as Amphitryon while the real husband fought distant wars against the Taphians. The sun god Helios refused to rise for three full days, extending one night into three so that Alcmene conceived Heracles during that single extended night.
Galanthis announced that the child had been safely delivered to trick the witch Lucina who prevented delivery for seven days and nights. As punishment for this deception, Galanthis transformed into a weasel but stayed by Alcmene's side.
After Amphitryon died, Alcmene married Rhadamanthys, son of Zeus, and they lived together in exile at Ocaleae in Boeotia. She gouged out the dead king Eurystheus' eyes using weaving pins before passing away or turning into stone depending on the account.
Homer wrote about Hera preventing Alcmene from giving birth so Eurystheus would rule first. Ovid described the struggle between Juno and the midwife Galanthis in his Metamorphoses while Plautus created a comedic play where Jupiter performed a miracle allowing quick and painless delivery.
Pausanias noted an altar dedicated to Alcmene stood in the Cynosarges district of Athens alongside altars for Heracles, Hebe, and Iolaus. The god in Delphi advised that her body should be buried there rather than in Argos or Thebes.