Source Verification: Alcmene
Every claim below is either what a named ancient source attests, in its own line or section, or a point where the sources themselves disagree.
What the Sources Attest
Why did Zeus disguise himself as Amphitryon?
Alcmene had made a condition of the marriage: she would not sleep with Amphitryon until he avenged her brothers, killed in a raid by the Teleboans. Zeus wanted to father a son on her and knew she would refuse any lover but her husband, so he took Amphitryon's exact appearance and arrived on the night the real Amphitryon was due back from that campaign, telling her of the victory as if he had won it himself.
Source: Apollodorus, Library 2.4.8
How long did the night Zeus spent with Alcmene last?
Apollodorus and later authors describe Zeus stretching the single night to three times its normal length, which is why Alcmene did not notice anything unusual until the real Amphitryon returned the next day and seemed no warmer toward her than the disguised god had been the night before.
Source: Apollodorus, Library 2.4.8
How did Amphitryon find out what had happened?
He noticed Alcmene did not greet him with any particular warmth, since as far as she knew they had already spent the previous night together. Confused, he consulted the seer Tiresias, who told him that Zeus had taken his form and slept with Alcmene the night before. Amphitryon still lay with her himself that same night, which is how Alcmene came to bear twin sons by two different fathers.
Source: Apollodorus, Library 2.4.8
Why was Heracles born after Eurystheus instead of before him?
Zeus announced that a descendant of Perseus about to be born, meaning Heracles, would rule all his kin. Hera, hostile to Alcmene, tricked Zeus into swearing an oath binding him to that exact wording, then had the birth goddess Eileithyia hold back Alcmene's labor while hurrying along the birth of Eurystheus, another descendant of Perseus born prematurely. Because Eurystheus was born first, the kingship and rule Zeus had sworn to bound to birth order went to him instead, which is why Heracles later serves Eurystheus rather than the reverse.
Source: Homer, Iliad 19.95-133
What did Hera do to the infant Heracles at Alcmene's house?
Once the twins Heracles and Iphicles were born, Hera sent two serpents into the nursery to kill Heracles in his cradle. The infant strangled both of them with his bare hands before anyone else in the household could intervene, an early sign, in the tradition, of the strength that would define his adult life.
Source: Apollodorus, Library 2.4.8
Where Accounts Differ
- how long the night lasted
- whether Amphitryon knew
- Apollodorus gives the connected narrative of the disguised night and the birth-order trick; Homer's Iliad is the earlier source for Hera delaying Alcmene's labor to favor Eurystheus, without naming Alcmene directly by the disguise story.
- Whether Amphitryon ever fully accepts Zeus's role, or resents it, is left ambiguous across sources; Plautus's comic treatment plays the situation for confusion rather than resolving it.
Sources
- Apollodorus, Library 2.4.8
- Homer, Iliad 19.95-133
- Euripides, Heracles
- Timothy Gantz, Early Greek Myth (1993)