Scion-tier (registry-floor) son of Sthenelus, the Mycenaean king who imposed the Twelve Labors on Heracles per Hera's instigation. The structural-narrative engine of the entire Heracles cycle. Killed at Athens (variant: by Hyllus per Apollodorus, or by Iolaus per Euripides) along with all five of his sons — the death terminating the Perseid-kingship-line at Mycenae and producing the dynastic vacuum that brought the Pelopid Atreidae to power.