26. Beltrán de la Cueva’s supposed affair with a Queen gave Isabella of Castile her throne.
Beltran de la Cueva was one of the favorite courtiers of King Henry IV of Castile. He was also reputed to have had an affair with Henry’s second wife, Joan of Portugal, the mother of the King’s only child, Juana. After Henry’s death, his half-sister Isabella claimed the throne of Castile because Juana was not Henry’s child — but Beltran’s. Rumors had long suggested that Beltran was Juana’s father because Henry was supposedly impotent. A four-year war ensued with Isabella emerging triumphant. But despite losing and the continued rumors about her parentage, Juana continued to sign her letters using the title “Queen”.
