John I (Portugal)

John I (John the Great), 1357?-1433, king of Portugal (1385-1433), illegitimate son of Peter I. He was made (1364) grand master of the Knights of Aviz and exercised his influence in opposition to Leonor Teles, the queen of his half brother, Ferdinand I . After Ferdinand's death (1383), his widow and her lover, the conde de Ourém, set up a regency in the name of Ferdinand's daughter Beatrice, wife of John I of Castile. This provoked a popular national revolt, led by John of Aviz, who murdered Ourém, and Nun' Álvares Pereira . The Castilians invaded (1384) Portugal, but their forces were decimated by the plague while they laid siege to Lisbon. John was elected king in 1385, and in the same year a great victory over the Castilians at Aljubarrota assured Portuguese independence (though peace was not finally concluded until 1411). John's position was strengthened by an alliance with England, sealed by a treaty (1386) and by John's marriage (1387) to Philippa, daughter of John of Gaunt . The reign of John the Great was one of the most glorious in medieval Portuguese history. His popularity was heightened by his administrative reforms. His sons, Duarte, Peter, Henry the Navigator, John, and Ferdinand, were important in inaugurating the era of Portuguese colonial and maritime expansion. Ceuta in N Africa was conquered from the Moors in 1415. John was succeeded by his son Duarte.

John I (or John the Great) (1357–1433) King of PORTUGAL (1385–1433), the illegitimate son of Pedro I. He led nationalist sympathizers against the Castilians, who supported Queen Eleanor, his rival. Defeating their invasion he went on to ally with England (through his marriage to Philippa, daughter of John of GAUNT) and to encourage African and Western exploration. His reign was the start of Portugal's period of colonial and maritime expansion; his sons, including HENRY THE NAVIGATOR, consolidated his achievements.

John I (1357–1433) King of Portugal (1385–1433). After the death of his half-brother, Ferdinand I, he resisted the proposed regency of Ferdinand's daughter, and was elected king. His reign marked the start of Portugal's maritime expansion.