Alfonso XI of Castile

Alfonso XI
Detail of a contemporary depiction in the Book of the Coronation of the Kings of Castile (14th century)
King of Castile and León
Reign	7 September 1312 – 26 March 1350
Predecessor	Ferdinand IV
Successor	Peter
Born	13 August 1311 Salamanca, Crown of Castile
Died	26 March 1350 (aged 38) Gibraltar, Emirate of Granada
Burial	Royal Collegiate Church of Saint Hippolytus
Spouses	Constanza Manuel ​ ​ (m. 1325; ann. 1327)​ Maria of Portugal ​ (m. 1328)​
Issue among others...	Peter Illegitimate: Henry II Fadrique, Lord of Haro Tello, Lord of Aguilar de Campoo Sancho, Count of Alburquerque
House	Castilian House of Ivrea
Father	Ferdinand IV of Castile
Mother	Constance of Portugal
Signature

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 his wife 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.