Duarte, Duke of Guimarães (1541–1576)
Duarte, Duke of Guimarães (March 1541, in Almeirim – 28 November 1576, in Évora) was a Portuguese infante (prince), son of Duarte of Portugal, 4th Duke of Guimarães and his wife, Isabel of Braganza. He served as Constable of the Kingdom, the highest military authority in the Portuguese Empire, second only to the monarch. Early life Through his father, he was a grandson of King Manuel I of Portugal; through his mother, he was a grandson of James, 4th Duke of Braganza. He was born posthumously and he inherited his father's titles and estates: the Dukedom of Guimarães. He was one of the most influential nobles during the reigns of Kings John III and Sebastian. Political career As member of the State Council he voted, in 1569, for the marriage of King Sebastian to Margaret of Valois (who later became Henry IV's first wife) and, in 1574, he escorted King Sebastian in his first trip to Tangiers, in north Africa. In 1557, when King John III died, Duarte was one of the three legitimate surviving male descendants of King Manuel I of Portugal (together with King Sebastian and Cardinal-Infante Henry). Personal life King Sebastian was jealous of this and several