The Dioscuri, the twins Castor and Pollux, most frequently appear on coins of the Roman Republic as horsemen galloping, with couched lances, and stars above their caps. Their mother was Leda, the queen of Sparta. Castor was the mortal son of Tyndareus, her husband, the king of Sparta. Pollux was the divine son of Zeus, who seduced Leda in the guise of a swan. When Castor was killed, Pollux asked Zeus to let him share his own immortality with his twin to keep them together, and they were transformed into the constellation Gemini. The pair were regarded as the patrons of sailors and were also associated with horsemanship.
