Castor and Pollux horse breaker and the boxer / Polydeuces, my brothers" ..." – Helen, "Iliad" 3.253–255), but in the "Odyssey" they are treated as alive even though "the corn-bearing earth holds them". The author describes them as "having honour equal to gods", living on alternate days because of the intervention of Zeus. In both the "Odyssey" and in Hesiod, they are described as the sons of Tyndareus and Leda. In Pindar, Pollux is the son of Zeus while Castor is the son of the mortal Tyndareus. The theme of ambiguous parentage is not unique to Castor and Pollux; similar characterisations appear in
Leda and the Swan (Michelangelo) Leda and the Swan (Michelangelo) Leda and the Swan is a lost tempera on canvas painting by Michelangelo, produced in 1530 but now only surviving in copies and variants. The work depicted the Greek myth of Leda and the Swan. In 1512 Alfonso I d'Este, Duke of Ferrara went to Rome to reconcile with Pope Julius II, who had excommunicated him in summer 1510 for his alliance with Louis XII of France against the Republic of Venice. Julius absolved him and Alfonso spent a few days in Rome before returning to Ferrara. On 11 July he visited the Sistine Chapel,