Eleanor was born as Leonor Núñez de Guzmán Ponce de León in 1310 in Seville in modern day Spain.
Her parents were nobles, and Eleanor’s great-grandfather was King Alfonso IX of León, meaning that her family was one of the highest ranking in the region. As a young girl, Eleanor was married off to a man named Juan de Velasco who died in 1328. Eleanor was left widowed at just eighteen years old.
Soon after the death of her husband, Eleanor encountered King Alfonso XI of Castile, León and Galicia. The king, who was a year younger than Eleanor, was so enthralled by her beauty that he made her his mistress. Alfonso had only recently married his wife Maria of Portugal, and so Eleanor was encouraged to try to arrange an annulment of the royal marriage before the couple had a chance to have any children. By refusing to do this, Eleanor resigned herself to a life as a royal mistress.
Alfonso and Maria soon had two children named Fernando and Pedro. Rather than bringing the royal family closer together, Alfonso completely ignored his wife after the birth of their children. With the royal duty of providing an heir complete, Alfonso wished to focus on his relationship with Eleanor his true love.
Eleanor was beautiful and intelligent and was so well loved, that she soon became the most powerful woman in the kingdom. Eleanor and the king were inseparable, and she was involved in all matters of state. When the king was unavailable, everybody from ambassadors to other monarchs would have to go through Eleanor who lived her life as if she was a queen.
Eleanor and Alfonso had ten children together during their twenty-year relationship. Each child was showered with riches and titles to make up for its lack of legitimacy. Alfonso also thanked his lover for every child by providing her with extensive lands and properties, making her a wealthy land owner in her own right. Eleanor’s family and friends also benefitted from her relationship with the king and were given the best positions at court. The aggrandisement of Eleanor’s kin led to her gaining many enemies, including the pope who went as far as pushing Portugal into invading Castile in 1340. After the war, Alfonso was forced to send Eleanor to a convent in order to make peace with his father-in-law who was king of Portugal. Once everything had settled down, Eleanor returned to court.
In 1350, King Alfonso died of the plague at the age of just thirty-eight. His death led to the fall of Eleanor and her faction as Queen Maria took control at court. Maria ordered for Eleanor to be imprisoned after accusing her of starting revolts against her son, the new King Pedro I. Sensing her own demise was near, Eleanor hastily arranged for the marriage of her son Henry to Juana Manuel who was the daughter of the realm’s most prosperous nobleman.
In 1351 at Talavera de le Reina, Eleanor was executed. It is believed that Maria the dowager queen had arranged the death of her rival, although there is no surviving evidence. Eleanor was not even given the honour of a respectable execution and instead died after having her neck sliced open with a dagger.
It was believed that Eleanor’s death would bring peace to the royal family, but it only made matters worse. The sons of Eleanor and King Alfonso were perpetually at war for the crown with their own half-brother King Pedro I. Eighteen years after the death of his mother Eleanor, her son Henry defeated King Pedro. Henry killed his half brother by stabbing him repeatedly at the Battle of Montiel and was subsequently proclaimed King Henry II of Castile. Eleanor’s illegitimate son had become a king, against all odds.