Alfonso XI of Castile

Alfonso XI (11 August 1311 – 26 March 1350), called the Avenger (el Justiciero), was King of Castile and León. He was the son of Ferdinand IV of Castile and Constance of Portugal. Upon his father's death in 1312, several disputes ensued over who would hold regency, which were resolved in 1313.

Once Alfonso was declared an adult in 1325, he began a reign that would serve to strengthen royal power and became known for his victory in the Battle of Rio Salado. While leading a siege against Yusuf I of Granada, he died of the plague in Gibraltar.

Source: Wikipedia — https://en.wikipedia.org/wiki/Alfonso_XI_of_Castile