Beltrán de la Cueva y Alfonso de Mercado, 1st Duke of Alburquerque was a Spanish nobleman who is said to have fathered Joanna, the daughter of Henry IV of Castile's wife Joan of Portugal. His alleged daughter, called "la Beltraneja", was deprived of the crown of Castile because of the uncertainty regarding her parentage.

Cuéllar is a municipality in the Province of Segovia, within the autonomous community of Castile and León, Spain.