The war had strengthened Joan II in his conviction that the future of Aragon lay in Castile, potentially much stronger than Aragon—Catalonia. Castile, however, was exhausted by decades of internecine fighting between opposing noble factions, a festering sore in the side of the Trastamaran dynasty. Joan encouraged a revival of the old Aragonese party, so as to weaken his personal enemy, Enrique IV, and also to exploit the struggle for the succession which was bound to follow Enrique’s death. On the death of his heir, Alfonso (June 1468), Enrique IV was forced to admit the illegitimacy of the infanta, Juana ‘la Beltraneja’, the fruit of one of his wife’s extra-marital affairs, and to proclaim as his new heir his half-sister, Isabel. This proclamation made it clear whom Ferdinand, Joan’s heir, should marry. His suit was supported in Castile by one of the noble factions (the archbishop of Toledo, the marquis of Villena and others) who hoped that the young prince of Aragon would be a strong condottiero whom they could bend to their cause. Other factions were hostile, but the Princess Isabel, the main interested party, openly stated her wish to marry Ferdinand. Given Enrique IV’s opposition to the idea of such a marriage, Isabel’s diplomatic strategies were extremely dangerous. Yet the marriage contract signed at Cervera established that the future sovereigns would take all decisions jointly, and that all decrees would bear both their signatures. However, de jure, the sole sovereign regnant would be Isabel. In several clauses added as a protocol at Aragonese insistence, it was established that Ferdinand would exercise the highest responsibilities in Castile, but that he would respect the rights and privileges of his Castilian subjects who alone would enjoy positions of public office in their country. Ferdinand, therefore, was relegated to the rank of consort and, furthermore, was obliged to put himself militarily at the disposal of Castile which he could not leave without permission. The marriage was celebrated at Valladolid on 18 October 1469 and when Enrique IV died in December 1474, Isabel had herself proclaimed queen and legitimate holder of the title to the kingdom of Castile. The problem of Ferdinand’s legal and constitutional position then arose once more. The Edict of Segovia (15 January 1475) referred to the queen as ‘the lady Isabel, queen of Castile, with Ferdinand her true husband’, a mode of address not appreciated by her spouse who had been king of Sicily since 1468, and was heir to the throne of Aragon. He therefore asked to be associated with the title of king. While, legally, the decision was merely expressing on paper the intention of the Cervera agreement by naming Isabel as the holder of the title to the crown and the line through whom that title should pass, Ferdinand’s position had changed (a fact which he mentioned with great satisfaction to his father) as his consort had delegated wide powers to him, enabling him to carry out the same functions as the queen. In 1481 Ferdinand conferred similar powers on his wife within the crown of Aragon.