Elektryon
As Elektryon was leaving to avenge the murder of his sons by the Teleboeans, he was accidentally killed by Amphitryon, consequently before Amphitryon could consummate his marriage to Alkmene he had to complete Elektryon’s blood feud and avenge the death of her brothers; while Amphitryon was off on this quest, Zeus came to Alkmene disguised as Amphitryon and from this union came the mighty hero Herakles (Heracles).