John I of Portugal

John I
King of Portugal and the Algarve, and Lord of Ceuta
Reign	6 April 1385— 14 August 1433
Predecessor	Beatrice (disputed)
Successor	Edward
Spouse	Philippa of Lancaster
Issue
Edward of Portugal Infante Pedro, Duke of Coimbra Henry the Navigator Infanta Isabel, Duchess of Burgundy Infante João, Lord of Reguengos de Monsaraz Infante Ferdinand, the Saint Prince Afonso, 1st Duke of Braganza (natural son) Beatrice, Countess of Arundel (natural daughter)
Father	Peter I
Mother	Teresa Lourenço
Born	11 April 1358 Lisbon, Kingdom of Portugal
Died	13 August 1433(1433-08-13) (aged 76) Lisbon, Kingdom of Portugal
Burial	Chapel of the Founder, Monastery of Batalha, Batalha, District of Leiria, Portugal

Portuguese royalty
House of Avis

John I Children    Infante Duarte (future Edward I)    Infante Pedro, Duke of Coimbra    Henry the Navigator (Infante Henrique, Duke of Viseu)    Infanta Isabel, Duchess of Burgundy    Infante João, Lord of Reguengos    Infante Fernando, the Saint Prince    Afonso, Duke of Braganza (illegitimate)    Beatriz, Countess of Arundel (illegitimate) Grandchildren include    Infanta Isabel of Coimbra, Queen of Portugal Edward Children    Afonso, Prince of Portugal (future Afonso V)    Infante Fernando, Duke of Viseu    Infanta Leonor, Holy Roman Empress    Infanta Catarina    Infanta Joana, Queen of Castile Grandchildren include    Infante Manuel, Duke of Beja (future Manuel I)    Infanta Leonor of Viseu, Queen of Portugal    Infanta Isabella, Duchess of Braganza Great-Grandchildren include    Jaime, Duke of Braganza, Prince of Portugal Afonso V Children include    João, Prince of Portugal    Blessed Joana, Princess of Portugal    João, Prince of Portugal (future John II) John II    Afonso, Prince of Portugal    Jorge, Duke of Coimbra (illegitimate)

John I (or João I, Portuguese pronunciation: [ʒuˈɐ̃w̃]; Lisbon, São João da Praça (extinct), 11 April 1357 – Lisbon, Castle, 14 August 1433), called the Good (sometimes the Great) or of Happy Memory, more rarely and outside Portugal the Bastard, was the tenth King of Portugal and the Algarve and the first to use the title Lord of Ceuta. He was the natural son of Peter I by a woman named Teresa Lourenço, who some say was a noble Galician, daughter of Lourenço Martins, o da Praça, and wife Sancha Martins. In 1364 he was created Grand Master of the Order of Aviz, by which title he was known. He became king in 1385, after the 1383–1385 Crisis.

On the death of his half-brother Ferdinand I in October 1383, without a male heir, strenuous efforts were made to secure the succession for princess Beatrice, Ferdinand's only daughter. As heiress presumptive, Beatrice had married king John I of Castile, but popular sentiment was against an arrangement in which Portugal would have become virtually united with Castile. The 1383–1385 Crisis followed, a period of political anarchy, when no monarch ruled the country.

On 6 April 1385, the council of the kingdom (cortes in Portuguese) met in Coimbra and declared John, then Master of Aviz, king of Portugal. This was in effect a declaration of war against Castile and its claims to the Portuguese throne. Soon after, the king of Castile invaded Portugal, with the purpose of conquering Lisbon and removing John I from the throne. John I of Castile was accompanied by French allied cavalry while English troops and generals took the side of John (see Hundred Years War). John I then named Nuno Álvares Pereira, his loyal and talented supporter, general and protector of the Kingdom. The invasion was repelled during the summer after the Battle of Atoleiros and, especially, the decisive battle of Aljubarrota ( 14 August 1385), where the Castilian army was virtually annihilated. John I of Castile then retreated and the stability of John I's throne was permanently secured.

On 11 February 1387, John I married Philippa of Lancaster, daughter of John of Gaunt, who had proved to be a worthy ally, consolidating the Anglo-Portuguese Alliance that endures to the present day.

After the death of John I of Castile in 1390, without leaving issue by Beatrice, John I of Portugal ruled in peace and pursued the economic development of the country. The only significant military action was the siege and conquest of the city of Ceuta in 1415. By this step he aimed to control navigation of the African coast. But in longer perspective, this was the first step opening the Arabian world to medieval Europe, which in fact led to the Age of Discovery with Portuguese explorers sailing across the whole world. It should be noted that the global Muslim population had climbed to about 8 per cent as against the Christian population of 14 per cent by 1400.

Contemporaneous writers describe him as a man of wit, very keen on concentrating the power on himself, but at the same time with a benevolent and kind personality. His youthful education as master of a religious order made him an unusually learned king for the Middle Ages. His love for knowledge and culture was passed to his sons: Duarte, the future king, was a poet and a writer, Pedro, the duke of Coimbra, was one of the most learned princes of his time and Prince Henry the Navigator, the duke of Viseu, started a school of navigation and invested heavily in science and development of nautical topics. In 1430, his only surviving daughter, Isabella, married Philip the Good, Duke of Burgundy and enjoyed an extremely refined court in his lands; she was the mother of Charles the Bold.

Genealogical data

Ancestry

Marriages and descendants

John I married at Oporto on 2 February 1387 Philippa of Lancaster, daughter of John of Gaunt, 1st Duke of Lancaster and Blanche of Lancaster. From that marriage were born several famous princes and princesses of Portugal (infantes) that became known as the Illustrious Generation<<Dudenha>> (Portuguese: Ínclita Geração).

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopædia Britannica (Eleventh ed.). Cambridge University Press. 

References

• Williamson, D. 1988. ‘’Debrett’s Kings and Queens of Europe’’