Twin sons of Zeus, Castor and Pollux, a stalwart pair of youths, of the Doric stock, great the former as a horse-breaker and the latter as a boxer; were worshipped at Sparta as guardians of the State, and pre-eminently as patrons of gymnastics; protected the hearth, led the army in war, and were the convoy of the traveller by land and the voyager by sea, which as constellations they are still held to be.