Leonor Telles de Menezes (or Teles de Meneses) (1350 – 27 April 1386) was a queen consort of Portugal and regent during the years 1383–1385. She was the wife of a Portuguese nobleman from whom she was forcibly divorced by King Ferdinand I, who afterward married her. She is called the Treacherous (Portuguese: a Aleivosa) by the Portuguese, who execrate her on account of her adultery and treason to her native country; she is considered "a sort of Portuguese Lucrezia Borgia".
A redheaded beauty, Dona Leonor Telles (or Teles) was the daughter of Martim Afonso Telo de Meneses, a nobleman in the Trás-os-Montes. She was great-great-great granddaughter of Teresa Sanches, the illegitimate daughter of King Sancho I of Portugal by his mistress Maria Pais Ribeira. At a young age she married Dom João Lourenço da Cunha, 2nd Lord of Pombeiro, with whom she had a son, Dom Álvaro da Cunha, 3rd Lord of Pombeiro, and a stillborn child.
Leonor's sister, Dona Maria Telles de Menezes, was a lady-in-waiting to the Infanta Beatrice, daughter of Peter I of Portugal and Inês de Castro. While visiting her sister Maria at court, Leonor had the privilege of attending Beatrice's marriage to Sancho, Count of Alburquerque. There, Leonor met Beatrice's elder half-brother, the Infante Ferdinand, heir to the Portuguese throne, who fell passionately in love with her and proceeded to seduce her, in spite of his promise to marry Eleanor, daughter of Henry II of Castile. Leonor did nothing to resist Ferdinand's advances and lashed out at her sister Maria for her attempts to prevent the affair from developing.
Queen of Portugal
Infante Ferdinand managed to annul Leonor's first marriage to João Lourenço da Cunha on grounds of consanguinity and on 5 May 1372 they were secretly married.
Upon the death of Ferdinand (1383), Leonor was nominated regent in the name of her daughter Beatrice. From 1383 onwards, Leonor ruled with her lover, João Fernandes Andeiro, 2nd Count of Ourém, also called "Conde Andeiro", which angered the nobility and the lower classes. Beatrice's marriage to the Castilian king John I led to the expulsion of both mother and daughter.
The loss of independence had been unthinkable for the majority of Portuguese nobles. A rebellion led by the Master of the Order of Aviz, future John I of Portugal, started in that year, leading to the 1383–1385 Crisis.
Leonor died in exile at a monastery at Tordesillas.