Early life. Alfonso was born in Madrid, Spain, the elder son of Infante Antonio, Duke of Galliera and his wife, Infanta Eulalia of Spain. On his paternal side he was a grandson of Antoine, Duke of Montpensier, while on his maternal side he was a grandson of Queen Isabella II of Spain.
Don Carlos María Isidro Benito de Borbón (29 March 1788 – 10 March 1855) was an Infante of Spain and the second surviving son of King Charles IV of Spain and of his wife, Maria Luisa of Parma. As Charles V , he was the first of the Carlist claimants to the throne of Spain .