In Greek mythology, the Dioscuri are the twin sons of Zeus and a mortal queen of Sparta, Leda Their mortal father was Tyndarus. Castor, a famous tamer of horses, and Pollux or Polydeuces, an excellent boxer, were also worshipped for their aid to sailors in distress.
They were devoted to each other, and in one myth, the mortal Castor is killed, but Pollux shares his immortality with his beloved twin. They are allowed by Zeus to spend half the year together in Hades and half the year alive.
In Greek art they are often shown wearing a hat similar to the pointed red Phrygian cap. They are the constellation Gemini, and were considered to be the cause of St. Elmo's fire. They were worshipped as part of a fertility cult, and by athletes.