The Catholic Monarchs (Spanish: los Reyes Catolicos) is the collective title used in history for Queen Isabella I of Castile and King Ferdinand II of Aragon. They were both from the House of Trastamara and were second cousins, being both descended from John I of Castile; they were given a papal dispensation to deal with consanguinity by Sixtus IV. The title of 'Catholic King and Queen' was bestowed on them by the Pope Alexander VI in 1496. They married on October 19, 1469, in the city of Valladolid; Isabella was 18 years old and Ferdinand a year younger. Their marriage united both crowns under the same family.