10 days ago · Castor and Pollux (or in Greek, Polydeuces) were twin brothers in Greek and Roman mythology, known together as the Dioscuri.. Their mother was Leda, but they had different fathers; Castor was the mortal son of Tyndareus, the king of Sparta, while Pollux was the divine son of Zeus, who seduced Leda in the guise of a swan.