Constance of Portugal, was Queen of Castile by her marriage to Ferdinand IV.
She was the eldest child and only daughter of King Denis of Portugal and his wife Elizabeth of Aragon, later Saint. Wikipedia
Born: January 3, 1290, Kingdom of Portugal
Died: November 18, 1313 (age 23 years), Sahagún, Spain
Grandchildren: Pedro I of Castile, Henry II of Castile, Fadrique Alfonso, and more
Parents: Denis I of Portugal and Elizabeth of Portugal
Children: Eleanor of Castile (1307–1359) and Alfonso XI of Castile
Spouse: Ferdinand IV of Castile (m. 1302)
Siblings: Afonso IV of Portugal and Afonso Sanches, Lord of Albuquerque