assembly of a burgher-packed Cortes to elect his brother Peter of Coimbra as regent for his nephew Afonso V. The high nobility, led by his half-brother Afonso of Barcelos, urged Eleanor to hold fast, and a tense power-sharing regency arrangement was agreed upon between Peter and Eleanor. Peter of Coimbra relied on his close alliance with Infante John to secure the lion's share of power during the first few years of the regency. Infante John's sudden death in October 1442 was a terrible blow to Peter, who thereafter found it increasingly difficult to fend off the aspirations of his half-brother Afonso of Barcelos. Regent Peter appointed John's son Diogo of Portugal to succeed his father as Master of the Order of Santiago and Constable of Portugal. Marriage and issue In 1424, John married his half-niece Isabella of Barcelos, daughter of his half-brother Afonso of Barcelos. The couple had four children: Infante Diogo of Portugal (1425–1443) – 4th Constable of Portugal and 11th Master of the Order of St. James; without issue. Infanta Isabella of Portugal (1428–1496), married John II of Castile, mother of Isabella I of Castile. Infanta Beatrice of Portugal (1430–1506), married Infante Ferdinand, Duke of Viseu, mother of Manuel I of Portugal. Infanta Phillipa of Portugal (1432–1444), Lady of Almada. Ancestry References "Nobreza de Portugal e do Brasil" – Vol. I, pages 296–297. Published by Zairol Lda., Lisbon 1989. 1400 births 1442 deaths 15th-century Portuguese people Constables of Portugal House of Aviz People from Santarém, Portugal Portuguese infantes Portuguese people of English descent Sons of kings