The marriage of Ferdinand and Isabella, second cousins, was carried out secretly and carefully, as her half-brother, then ruling Castile, preferred to marry her to a brother of the French king, Louis XI.
Isabella I of SpainQueen Isabellas in History Beatriz Galindo, La Latina
Catherine of Aragon FactsCatherine of Aragon: Early Life and First Marriage Catherine of Aragon: Marriage to Henry VIII