In Greek mythology, Rhadamanthus or Rhadamanthys (Ancient Greek: Ῥαδάμανθυς) was a wise king of Crete, son of Zeus and Europa and brother of Minos and Sarpedon. Renowned for inflexible justice, he legislated for the Cretans, was driven from Crete by Minos, and in later tradition became one of the three judges of the dead — or a ruler in Elysium beside Cronus. His name yields the English adjective rhadamanthine, "sternly just."
Adapted from Wikipedia, "Rhadamanthus" · CC BY-SA 4.0
I.Family
Usually son of Zeus and Europa, brother of Minos and Sarpedon, and raised by the stepfather Asterion. He is father of Gortys (linked to Gortyn) and Erythrus (founder of Erythrae). A minority genealogy in Pausanias (citing Cinaethon) makes him son of Hephaestus in a Cretan line from Talos and Cres. Some sources, including Plutarch's Theseus, make him husband of Ariadne and father of Oenopion, Staphylus, and Thoas — a tradition that must be kept distinct from Dionysus's Ariadne.
II.Lawgiver and exile
Before or beside his underworld role he is a legislator: one law has Cretans swear by animals; another absolves those who defend themselves against initiators of violence. Plato's Laws introduces him as Minos's brother and the justest of men. When childless Asterius dies and Minos takes the throne, jealousy of Rhadamanthus's popularity drives him from Crete. He flees to Boeotia, marries Alcmene after Amphitryon's death, and in some accounts tutors young Heracles in archery. Ancient authors often place his activity among the Aegean islands and in central Greece rather than on Crete itself.
III.Judge of the dead
Later legend (c. 400 BCE onward) sets him among the judges of the dead with half-brother Aeacus and full-brother Minos. Plato's Gorgias assigns him the souls of easterners, Aeacus westerners, and Minos the casting vote. Virgil's Aeneid makes him a punisher in Tartarus. Homer, however, places him in the Elysian Fields (Odyssey 4); Pindar makes him Cronus's right-hand man in Elysium and sole judge of the dead; Lucian's True History seats him among heroes on the Isles of the Blest.