In Greek mythology, Proetus (Ancient Greek: Προῖτος), son of Abas, was a king of Argos and Tiryns — twin brother and lifelong rival of Acrisius. Driven from Argos, he returned with Lycian aid, fortified Tiryns with Cyclopean walls, and became the host of Bellerophon and the father of the mad Proetides.
Adapted from Wikipedia, "Proetus (son of Abas)" · CC BY-SA 4.0
I.Family
Proetus and Acrisius were twin sons of Abas, king of Argos, by Aglaea or Ocalea. Abas himself was son of the Aegyptiad Lynceus and the Danaid Hypermnestra. By his wife Antea (Homer) or Stheneboea (later mythographers), Proetus fathered the three Proetides — Lysippe, Iphinoe, and Iphianassa in the Bibliotheca — and a son Megapenthes. Some sources give other names for the daughters.
Apollodorus notes that some said Proetus was father of Perseus; the usual tradition makes Perseus the grandson of Acrisius through Danaë.
II.Rivalry with Acrisius
The twins quarreled even in the womb and carried the feud into adulthood; tradition credits them with inventing shields or bucklers in the course of their wars. Proetus first held Argos for about seventeen years, then was defeated and driven into exile. He fled to King Iobates (or Amphianax) in Lycia, married the king's daughter Antea or Stheneboea, and returned with a Lycian army. After further fighting the kingdom was divided: Acrisius kept Argos, while Proetus received Tiryns and the eastern half of Argolis — the Heraeum, Midea, and the coast — and Tiryns was fortified by the Cyclopes.
In one strand of the tradition the conflict was renewed when Proetus seduced Acrisius's daughter Danaë.
III.Bellerophon and the Proetides
When Bellerophon came to Proetus for purification, the queen fell in love with him; refused, she accused him before Proetus of improper advances. Proetus sent Bellerophon to Iobates in Lycia with a sealed letter requesting his death — the famous letter of Bellerophon that opens the Iliad's Lycian digression.
When the Proetides reached maturity they were stricken with madness — variously blamed on Dionysus for scorning his worship, or on Hera for pride or for stripping gold from her statue. They wandered the Peloponnese until Melampus cured them in return for a third of the kingdom, then demanded an equal third for his brother Bias. Iphinoe died in the chase; the remaining sisters married Melampus and Bias. Some accounts place the cure at Anigros, Cleitor, or Lusi in Arcadia, or credit Asclepius.
IV.Death
In Ovid, Proetus is turned to stone when Perseus — grandson of the rival Acrisius — forces him to look on Medusa's head. Later Megapenthes exchanges kingdoms with Perseus. This article concerns the Argive twin of Acrisius, not other bearers of the name.