Juan de Alfaro first studied under Antonio del Castillo at Seville, and subsequently in the school of Velasquez at Madrid. After his return to Seville, he was wont to plume himself upon the knowledge of art which he had acquired in the school of that great painter; and he also signed all his pictures in a conspicuous manner, "Alfaro, pinxit." This was too much for Castillo, and he accordingly inscribed his Baptism of St. Francis, executed for the Capuchin convent, where his juvenile rival was likewise employed, "Non pinxit Alfaro." Years after, Palomino became sufficiently intimate with Alfaro, to ask him what he thought of Castillo's sarcastic inscription. "I think," replied the unabashed object of the jest, "that it was a great honor for me, who was then a beardless boy, to be treated as a rival by so able an artist."