Mayor Guillén de Guzmán ( ?, 1205 - Alcocer, 1262 ).
Born into one of the level two "richmen" families of King Ferdinand III's court, she was the daughter of Guillén Pérez de Guzmán, and sister of Pedro de Guzmán, Castile's first adelantado and father of Alonso Pérez de Guzmán.
She was mentioned in chronicles and documents of the time mainly for being the lover of prince Alfonso de Castilla, future king Alfonso X of Castile, son of Ferdinand III of Castile and Beatriz de Suabia.
From her relation with prince Alfonso she had three children:
She died on 4 October 1262. Her body was buried in the monastery of the Order of Poor Ladies of San Miguel del Monte. After moving to Alcocer, her body was moved as well, and it curiously remained intact until the beginning othe 21st century. In 1936, it disappeared together with a polycromated wooden statue, considered among he best funerary art from the Middle Ages in Guadalajara.