John of Portugal ( ), occasionally surnamed Castro (1352), was the eldest surviving son of King Peter I of Portugal by his mistress Inês de Castro. He was a potential but unsuccessful contender for the Portuguese throne during the 1383–85 crisis of succession. Background John was the son of the Portuguese King Peter I and his lover Inês de Castro, a Galician noblewoman who had arrived in Portugal as a lady-in-waiting to Infanta Constance of Castile, recently married to Pedro I (royal heir at the time). The status of John as Infante of Portugal is a debatable subject. Some historians consider him a natural son of Peter I, and so assert that the title 'Infante of Portugal' could not be attributed to him. Others refer to the circumstances of the death of Inês de Castro, ordered by Peter's father, King Afonso IV of Portugal: after inheriting the throne, the Prince admitted he had married Inês secretly, therefore she was a lawful Queen of Portugal and he was legitimized as Infante of Portugal. Life The Duke Infante lived at the Court of Ferdinand I, and was esteemed as a good knight, a dexterous rider and able hunter, valiant in shooting. He had a steady friendship with the Master of Avis, his half-brother, who was valiant and daring as he, but very different in character. Infante John was a dissembler, ambitious and bold, and would not hesitate to act or speak in pursuit of his ambition. He fell in love with María Teles de Meneses (c. 1338, CoimbraNovember 1379, Coimbra), a redheaded beauty about fourteen years older than he, who was lady-in-waiting to the Infanta Beatrice and sister of Queen Leonor Teles. María was the widow (circa 1360) of Álvaro Dias de Sousa (1365), 2nd Lord of Mafra and Ericeira, by whom she had conceived Lopo Dias de Sousa ( – 1435, Pombal), who inherited his father's titles and later became Master of the Order of Christ. Infante John, having gone to her house to fetch her, found an altar and a priest waiting; María had made the preparations for their wedding. Thus the marriage was performed secretly in 1376, and when it became public knowledge, it provoked the wrath of Leonor Teles. Upon the death of Ferdinand I with no male heir, the people might demand the crowning of the beloved Infante John as king, which would raise his wife to