In Greek mythology, Polydectes was the king of Seriphos who sent Perseus to fetch Medusa’s head.
Polydectes wanted to marry Danaë, Perseus’s mother, but Perseus opposed the match. To remove the young hero, Polydectes staged a feast and asked each guest for a horse. Perseus could not provide one, so he offered something far more dangerous: Medusa’s head.
The seemingly impossible request launched Perseus’s quest. With divine assistance, he found the Gorgons, killed the mortal Medusa, and returned carrying her head. Polydectes is sometimes confused with Acrisius, Danaë’s father, who was responsible for casting Danaë and Perseus adrift. Polydectes was instead the ruler whose marriage plan created the immediate danger in the Seriphos episode.