Prince Baltasar Carlos was the only son of Philip IV of Spain by his first marriage, to Elisabeth of France (Isabel de Borbón). Though he only lived until he was 16, when he died of smallpox, he was painted on numerous occasions, sitting to both Velázquez (see for example the notable portraits in the Prado, Madrid, showing him on horseback and in hunting attire) and Juan Bautista Martinez del Mazo. August Mayer was the first to propose that the present picture was possibly connected with a lost original by Velázquez, although he does not exclude that it could also be related to a lost Mazo (loc. cit.).