
Two years later, he had the marriage annulled so he could marry Afonso's daughter, Maria of Portugal. In 1325 Alfonso XI of Castile entered a child-marriage with Constanza Manuel of Castile, the daughter of one of his regents. The first-born of this union was a daughter, Maria of Portugal. In 1309, Afonso married Beatrice of Castile, daughter of King Sancho IV of Castile and María de Molina. After a few failed attempts at invasion, the brothers signed a peace treaty, arranged by Afonso IV's mother, Elizabeth. From Castile, Afonso Sanches orchestrated a series of attempts to usurp the crown. On 7 January 1325, Afonso IV's father died and he became king, whereupon he exiled his rival, Afonso Sanches, to Castile, and stripped him of all the lands and fiefdom given by their father.


The notorious rivalry between the half brothers led to civil war several times.

However, he was not Denis' favourite son, the old king preferring his illegitimate son, Afonso Sanches. Afonso, born in Lisbon, was the rightful heir to the Portuguese throne.
