daughter Maria was being mistreated by her husband King Alfonso XI of Castile. Don Juan Manuel had "an opportunity to being compensate for the procedure of his sovereign", and made an alliance with the Portuguese monarch (who felt as though his daughter was being dishonored), sealed with the marriage of Constanza to the heir of the Portuguese throne, Infante Pedro. The contract for the wedding, signed in 1335 stipulated, among other things, that: Constanza would maintain the manors and the free disposition of the lands delivered for the sustenance of her house; her father could visit her as many times as he wanted; the first son of the marriage would inherit the crown of Portugal while the second son would succeed to the House of Manuel but, if this second-born son was not born, the House of Manuel would be inherited by the Infante Pedro or his heir; and, that under no circumstances would the lands of Don Juan Manuel join those of the Crown of Castile. This agreement was not to the liking of the Castilian monarch who did everything possible to prevent Constanza from traveling to Portugal and imprisoned her at the Alcázar of Toro to pressure Don Juan Manuel to desist from this marriage. Don Juan Manuel claimed his daughter but King Alfonso XI refused to give her up. However, the marriage by proxy was celebrated, first in Portugal, on 28 February 1336 at the Convent of São Francisco in Évora with the presence of Infante Pedro, his parents and several bishops, and, as proxies of Constanza, Fernão and Lopo Garcia. Although the bride and groom were 2nd cousins (being both great-grandchildren of King Pedro III of Aragon), it did not take long to obtain the papal dispensation. The Portuguese King felt offended by the fact that King Alfonso XI still held Constanza in Toro, as well as by the humiliating treatment of the Castilian monarch towards his wife, María of Portugal, while King Alfonso XI reproached his father-in-law for not lending him the promised help in the fight against the Moors. This led to a war between the two kingdoms that lasted three years and raised the concern of other Christian kingdoms and Pope Benedict XII, who played a crucial role in ending this conflict. Peace between the Kingdoms of Castile and Portugal was agreed in Seville in the summer of 1339. Don Juan Manuel gave