Dioscuri.

    Castor and Polydeuces (Pollux) were the twin sons of Leda and the brothers of Helen and Clytemnestra. Their paternity is uncertain: according to some accounts, both boys were the sons of Leda’s mortal husband, King Tyndareus of Sparta, and thus are sometimes called the Tyndaridae; the Homeric Hymns and other sources say their father was Zeus (Jupiter) in the guise of a swan, and give them the epithet “Dioscuri” (“sons of Zeus”). Most ancient accounts, however, state that Castor was Tyndareus’s son, and thus mortal, and that Polydeuces was the son of Zeus, and therefore immortal.
    Castor was known for his ability with horses, while his brother’s fame lay in his skill as a boxer. The brothers joined Meleager in the Calydonian boar hunt and Jason in the Argonautic expedition, during which Polydeuces distinguished himself in a fist fight with Amycus, son of Poseidon, whom he killed. The twins also went to Attica to recover their sister Helen after Theseus abducted her.
    The Dioscuri quarreled with another set of twins, Idas and Lynceus, over Phoebe and Hilaera, the daughters of Leucippus. Castor and Polydeuces abducted the young women (and some sources say raped them) on the day they were to be married to Idas and Lynceus. In a pitched battle. Castor and both of the expectant bridegrooms were killed. Polydeuces begged Zeus to restore his brother to life, or to allow himself to die. When Zeus refused, Polydeuces offered to share his immortality with his brother. According to Pindar (who ascribes the fatal quarrel to a dispute over cattle, not women), the brothers henceforth lived half the time on Olympus, half in Hades (or, according to Homer, they were alive on alternate days).
    The Dioscuri were worshiped as protectors of seafarers from the sixth century BCE, taking the form of the twin lights of St. Elmo’s fire. In Euripides’ Electra they appear as protectors of the sailors and champions of just and moral men. When the pair became immortal, they were placed in the heavens as the constellation Gemini. Their cult was worshiped as early as the fifth century BCE in Sparta, but it was during the Roman period that it gained fame. They were said to appear as horsemen on white mounts during the battle of Lake Regillus (496 CE), which led to a great Roman victory. A temple to the twin deities was located in the Forum at Rome, and equestrian statues of them are in the Piazza Quirinale on Monte Cavallo. As horsemen, they were patrons of the Roman order of equites.
    In the postclassical period, the rape of the Leucippides, also a popular theme in ancient art, is the most commonly treated of all the adventures of the Dioscuri.