of 1386, he was commissioned to defend Andalusia from Portuguese attacks. Later in the year, when John of Gaunt (uncle of the English king Richard II) invaded northern Castile to try to claim the throne for himself, Infante John made a series of incursions into Portuguese territory, but failed to garner significant support for his own pretensions to the Portuguese crown. For his loyalty to Castile, in 1387 John was created duke of Valencia de Campos (renamed Valencia de Don Juan in his honor), a rank which adjoined him to the upper echelons of Castilian nobility. Castile's truces with England and Portugal from 1388 onwards seem to have eclipsed Duke John from any significant political role, and he kept a relatively low profile until his death. John's precise date of death is unclear. He could have died in or after 1393 and before 1397, when his younger brother Denis, Lord of Cifuentes, received support from legitimists in Portugal (implying that his older brother, who would have had a better claim, was already deceased). The chronicler Fernão Lopes said that he was dead by 1397. On 19 September 1396, Henry III of Castile confirmed on John's daughters their right to succeed in their father's county of Valencia de Don Juan, suggesting that John may have been dead by then. The Portuguese genealogist Anselmo Braamcamp Freire cites a letter from John I of Portugal, dated 20 September 1400, in which he refers to his deceased namesake half-brother, but he also suggests that the date might be wrong due to statements that Duke John was active in 1402 in confirming privileges given by Henry III of Castile to Palencia Cathedral. John's estates were partitioned between his legitimate daughters on 2 November 1404 at Medina del Campo. None of the children of Inés de Castro were buried in their native land. John's brother, Infante Denis, was buried at the Monastery of Santa María de Guadalupe, his sister Beatriz in the Cathedral of Burgos, and John at the Convent of San Esteban in Salamanca. Titles and styles Duke of Valencia de Campos (22 December 1387– 1396?) Lord of Alba de Tormes (15 December 1385– 1396?) Issue His first marriage, in 1376, was to Maria Teles de Meneses, the widow of Alvaro Dias de Sousa. She was the daughter of Martim Afonso Telo de Meneses and his wife Aldonça Anes de Vasconcelos. From this marriage he