Eleanor de Guzmán

Leonor (Eleanor) de Guzmán y Ponce de León (1310–1351) was a Castilian noblewoman. After about 1330, she became the long-term mistress and favourite of Alfonso XI, with whom she had the illegitimate son Henry "the Fratricidal", future first monarch of the House of Trastámara. She held the lordship of Medina-Sidonia until she fell from grace in the wake of Alfonso's death in 1350. She was then executed by her enemies.