John I of Portugal (Lisbon, April 11, 1357 – Lisbon, 14 August 1433), was the tenth King of Portugal and the first of the Avis Dynasty, surnamed The Good Memory for your legacy.
Illegitimate child (bastard) of King Pedro I, Master of the Order of Avis (based in Avis, Alentejo), as king following the crisis of 1383 to 1385 that threatened the independence of Portugal.
With the support of the kingdom constable, Nuno Alvares Pereira, and British allies fought the battle of Aljubarrota against the Kingdom of Castile, who had invaded the country. The victory was decisive: Castile retired, ending several years later by the officially recognized as king.
To seal the Luso-British alliance married Philippa of Lancaster, daughter of John of Gaunt, dedicating himself since the development of the kingdom.
In 1415 conquered Ceuta, strategic square for navigation in North Africa, which would start the Portuguese expansion. There were armed horsemen their children Duarte, Pedro and Prince Henry, called the brothers illustrious generation.
John was born in Lisbon as the natural son of Peter I by a woman named Teresa, who, according to Fernão Lopes, was a noble Galician. In the 18th century, António Caetano de Sousa found a 16th-century document in the archives of the Torre do Tombo, wherein she was named as Teresa Lourenço. In 1364, by request of D. Nuno Freire de Andrade, a Galician Grand Master of the Order of Christ, he was created Grand Master of the Order of Aviz, by which title he was known.
On the death of his half-brother Ferdinand I without a male heir in October 1383, 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 been virtually annexed by 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 (the Portuguese Cortes) met in Coimbra and declared John, then Master of Aviz, King of Portugal. This was followed by the liberation of almost all of the Minho in the course of two months, in the war against Castile and its claims to the Portuguese throne. Soon after, the King of Castile again 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 of Aviz (see Hundred Years’ War). John and Nuno Álvares Pereira, his Constable and talented supporter, repelled the attack on the decisive Battle of Aljubarrota (14 August 1385). John I of Castile then retreated. The Castilian forces abandoned Santarém, Torres Vedras, Torres Novas, many other towns were delivered to John I by Portuguese nobles from the Castilian side and the stability of the Portuguese 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 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.
The raids and attacks of the Reconquista created captives on both sides, who were either ransomed or sold as slaves. The Portuguese crown extended this to North Africa. After the attack on Cueta, the king sought papal recognition of it as a crusade. Such as determination would then indicate that those captured could legitimately be sold as slaves.
John I requested and obtained from Pope Martin V a Papal bull, Sane charissimus, of 4 April, 1418, confirming to the king all the lands he should take from the Moors. Political weakness compelled the Renaissance Papacy to adopt an acquiescent and unchallenging position when approached for requests for privileges in favour of these ventures. Under the auspices of Prince Henry the Navigator, voyages were organized which ultimately led to the discovery of the Cape of Good Hope.
The ill result of the expedition against Tangier, which was undertaken against the advice of Eugenius IV and ended in the captivity of the Infanta Ferdinand, hastened the end of John I, and his son Alfonso V (1438-81) succeeded to the throne.
Contemporaneous writers describe John as a man of wit, very keen on concentrating 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, often collectively referred to by Portuguese historians as the “illustrious generation” (Ínclita Geração): Edward, the future king, was a poet and a writer; Peter, the Duke of Coimbra, was one of the most learned princes of his time; and Prince Henry the Navigator, the duke of Viseu, invested heavily in science and the development of nautical pursuits. In 1430, John’s only surviving daughter, Isabella, married Philip the Good, Duke of Burgundy, and enjoyed an extremely refined court culture in his lands; she was the mother of Charles the Bold.