Leonor Teles was queen consort of Portugal by marriage to King Ferdinand I, and regent of Portugal. She was one of the protagonists, along with her brothers and her daughter Beatrice, of the events that led to the succession crisis of 1383–1385, which culminated in the defeat of her son-in-law King John I of Castile and his armies in the Battle of Aljubarrota. Called "the Treacherous" by her subjects, who execrated her on account of her adultery and treason to her native country, she was dubbed by historian Alexandre Herculano as "the Portuguese Lucrezia Borgia".

Beatrice was the only surviving legitimate child of King Ferdinand I of Portugal and his wife, Leonor Teles. She became Queen consort of Castile by marriage to King John I of Castile. Following her father's death without a legitimate male heir, she claimed the Portuguese throne, but lost her claim to her uncle, who became King John I of Portugal, founder of the House of Aviz.