Isabel of Braganza, Duchess of Guimarães Isabel of Braganza, Duchess of Guimarães Dona Isabel of Braganza (1514 – 16 September 1576) was a member of the House of Braganza, daughter of Jaime, Duke of Braganza (a nephew of Manuel I of Portugal) and Leonor Pérez de Guzmán. Isabel married her cousin Infante Duarte a son of Manuel I and Maria of Aragon in 1537. Isabel was dowried with the Dukedom of Guimarães, which had belonged to her brother Teodósio I, Duke of Braganza. After the marriage, Infante Duarte became the 4th Duke of Guimarães. Her younger daughter Catherine became the Duchess of Braganza and had a
Fernando II, Duke of Braganza focused on diminishing the powers of the two most powerful noble houses in the kingdom, House of Beja and Viseu and the House of Braganza. King John II accused his first cousin, Diogo I of Beja and Viseu (brother-in-law of Fernando II), of high treason and had him brutally executed. Soon after, the King also accused his second half-cousin, Fernando II of Braganza, of high treason and had him executed at Évora in 1483. Afterwards, the assets of the House of Braganza were confiscated and the family fled to Castile. The family returned in 1498 and had all their property