shifting coalitions of nobles, namely the Infantes of Aragon Henry and John of Aragon, brothers of John II's wife Maria, who, under the pretence of freeing the King from the undue influence of his favourite, were intent on making a puppet of him for their own ends. The part which Álvaro de Luna played has been diversely judged. The Encyclopædia Britannica Eleventh Edition recounts that to Juan de Mariana he appears as a mere self-seeking favourite. To others, he has seemed to be a loyal servant of the King who endeavoured to enforce the authority of the crown, which in Castile was the only alternative to anarchy. He fought for his own ends, but his supremacy was perhaps better than the rule of lawless alliances of plundering nobles. In 1427, he was solemnly expelled by a coalition of the nobles, only to be recalled in the following year. In 1431, he endeavoured to employ the restless nobles in a campaign for the reconquest of Granada, the remaining territory of Muslim Spain and then ruled by the sultan Muhammed IX. Some successes were gained at the Battle of La Higueruela, but in the end de Luna failed. A consistent policy was impossible with a rebellious aristocracy and a king of indolent character. In 1445, the faction of nobles allied with Álvaro's main enemies, the Infantes of Aragon, were defeated at the First Battle of Olmedo. One of them, Infante Henry, Duke of Villena, brother of the Queen, died of his wounds. Luna, who had been Constable of Castile and Count of San Esteban de Gormaz since 1423, became Grand Master of the Order of Santiago by election of the Knights. Downfall Queen Maria died under suspicious circumstances, pointing to Luna as the mastermind. Nevertheless, his power appeared to be thoroughly established. It was, however, based only on the personal affection of the King. The King's second wife, Isabella of Portugal, although her whole royal marriage was a product of Luna's arrangements, was soon offended by the immense influence of the Constable, and when the murder of the King's accountant Alfonso Pérez de Vivero was suspected to have been at Luna's orders, she urged her husband to free himself from thralldom to his favourite. In 1453, the King succumbed to his wife's demands; Luna was arrested, tried and condemned to death, and soon executed by beheading at Valladolid on 2 June 1453.