John I of Portugal in the context of "1383–85 crisis"

Prince Henry of Portugal, Duke of Viseu (Portuguese: Infante Dom Henrique; 4 March 1394 – 13 November 1460), better known as Prince Henry the Navigator (Portuguese: Infante Dom Henrique, o Navegador), was a Portuguese prince and a central figure in the early days of the Portuguese Empire and in the 15th-century European maritime exploration. Through his administrative direction, he is regarded as the main initiator of what would be known as the Age of Discovery. Henry was the fourth child of King John I of Portugal, who founded the House of Aviz.

After procuring the new caravel ship, Henry was responsible for the early development of Portuguese exploration and maritime trade with other continents through the systematic exploration of Western Africa, the islands of the Atlantic Ocean, and the search for new routes. He encouraged his father to conquer Ceuta (1415), the Muslim port on the North African coast across the Straits of Gibraltar from the Iberian Peninsula. He learned of the opportunity offered by the Saharan trade routes that terminated there, and became fascinated with Africa in general; he was most intrigued by the Christian legend of Prester John and the expansion of Portuguese trade. He is regarded as the patron of Portuguese exploration. He is also considered to be one of the most responsible for developing the slave trade in Western Europe. The prince died on 13 November 1460 in Vila do Bispo, Algarve.

The Portuguese conquest of Ceuta took place on 21 August 1415, between Portuguese forces under the command of King John I of Portugal and the Marinid sultanate at the North African city of Ceuta. The city's defenses fell under Portuguese control after a carefully prepared attack, and the successful capture of the city marked the beginning of the Portuguese Empire. Ceuta remained under Portuguese control until being transferred to Spain in 1668.

An interregnum and a war of succession began in the Kingdom of Portugal in 1383 when King Ferdinand I died leaving no sons and ended when King John I was crowned in 1385 after his victory during the Battle of Aljubarrota.

The Portuguese interpret the era as their earliest national resistance movement to counter Castilian intervention, and Robert Durand considers it as the "great revealer of national consciousness".

The House of Aviz (Portuguese: Casa de Avis [ɐˈviʃ]), also known as the Joanine Dynasty (Dinastia Joanina), was a dynasty of Portuguese origin which flourished during the Renaissance and the period of the Portuguese discoveries, when Portugal expanded its power globally.

The house was founded by King John I of Portugal, Grand-Master of the Order of Aviz and illegitimate son of King Pedro I (of the Portuguese House of Burgundy), who ascended to the throne after successfully pressing his claim during the 1383–1385 Portuguese interregnum. Aviz monarchs would rule Portugal through the Age of Discovery, establishing Portugal as a global power following the creation of the Portuguese Empire. In 1494, Pope Alexander VI divided the world under the dominion of Portugal and Spain with the Treaty of Tordesillas.

The Most Serene House of Braganza (Portuguese: Sereníssima Casa de Bragança), also known as the Brigantine dynasty (dinastia Brigantina), is a dynasty of emperors, kings, princes, and dukes of Portuguese origin which reigned in Europe and the Americas.

The house was founded by Afonso I, 1st Duke of Braganza, illegitimate son of King John I of Portugal of the House of Aviz, and would eventually grow into one of the wealthiest and most powerful noble houses of Iberia during the Renaissance period. The Braganzas came to rule the Kingdom of Portugal and the Algarves after successfully deposing the Philippine Dynasty in the Restoration War, resulting in the Duke of Braganza becoming King John IV of Portugal, in 1640. The Braganzas ruled Portugal and the Portuguese Empire from 1640 and with the creation of the United Kingdom of Portugal, Brazil and the Algarves, in 1815, and the subsequent independence of the Empire of Brazil, in 1822, the Braganzas came to rule as the monarchs of Brazil.

Portugal had only two queens regnant: Maria I and Maria II (and, arguably, two more: Beatriz for a short period of time in the 14th century; and Teresa, in the 12th century, which technically makes her the first ruler and first queen of Portugal).

The other queens were queens consort, wives of the Portuguese kings. Many of them were highly influential in the country's history, either ruling as regents for their minor children or having a great influence over their spouses.

John I (Spanish: Juan I; 24 August 1358 – 9 October 1390) was King of Castile and León from 1379 until 1390. He was the son of Henry II and of his wife Juana Manuel of Castile. John ascended to the throne in 1379 and in 1383, he married Beatrice, the daughter of King Ferdinand I of Portugal. When Ferdinand died that same year, John, aiming to enforce his claim on the Portuguese crown through his wife, brought the country into the 1383–1385 Crisis. His forces faced resistance from Portuguese factions supporting John of Aviz. The conflict culminated in the Battle of Aljubarrota in 1385, where John suffered a defeat, ensuring Portugal's independence.

To secure Castile, he married his son Henry to the daughter of John of Gaunt, linking the Trastámara and Plantagenet dynasties. He died in 1390 when he fell from his horse during a fantasia performance. His death led to minority rule under his son, Henry III.

Isabella of Portugal (Portuguese: Isabel de Portugal; 21 February 1397 – 17 December 1471) was Duchess of Burgundy from 1430 to 1467 as the third wife of Duke Philip the Good. Their son was Charles the Bold, the last Valois Duke of Burgundy.

Born a Portuguese infanta of the House of Aviz, Isabella was the only surviving daughter of King John I of Portugal and his wife Philippa of Lancaster. She served as the regent of the Burgundian Low Countries during the absence of her spouse in 1432 and in 1441–1443. Isabella served as her husband's representative in negotiations with England regarding trade relations in 1439 and those with the rebellious cities of Holland in 1444.

John of Gaunt, Duke of Lancaster (6 March 1340 – 3 February 1399), was an English prince, military leader and statesman. He was the fourth son (third surviving) of King Edward III, and the father of King Henry IV. Because of Gaunt's royal origin, advantageous marriages and some generous land grants, he was one of the richest men of his era and an influential figure during the reigns of both his father and his nephew, Richard II. As Duke of Lancaster, he is the founder of the royal House of Lancaster, whose members would ascend the throne after his death. His birthplace, Ghent in Flanders, then known in English as Gaunt, was the origin of his name.

John's early career was spent in France and Spain fighting in the Hundred Years' War. He made an abortive attempt to enforce a claim to the Crown of Castile that came through his second wife, Constance of Castile, and for a time styled himself as King of Castile. When Edward the Black Prince, Gaunt's elder brother and heir-apparent to the ageing Edward III, became incapacitated owing to poor health, Gaunt assumed control of many government functions and rose to become one of the most powerful political figures in England. He was faced with military difficulties abroad and political divisions at home, and disagreements as to how to deal with these crises led to tensions between Gaunt, the English Parliament and the ruling class, making him an unpopular figure for a time. He helped forge the 1386 Anglo-Portuguese alliance, secured through the marriage of his daughter Philippa to John I of Portugal, which endured for centuries.

Duke of Viseu (in Portuguese Duque de Viseu) was a Portuguese Royal Dukedom created in 1415 by King John I of Portugal for his third male child, Henry the Navigator, following the conquest of Ceuta.

When Henry the Navigator died without issue, his nephew, Infante Ferdinand of Portugal (King Edward, King of Portugal's younger son), who was already Duke of Beja, inherited the Dukedom of Viseu and, when his younger son became King of Portugal as Manuel I, this became a royal Dukedom.

The Battle of Aljubarrota was fought between the Kingdom of Portugal and the Crown of Castile on 14 August 1385. Forces commanded by King John I of Portugal and his Constable Nuno Álvares Pereira, with the support of English allies, opposed the army of King John I of Castile with its Aragonese and French allies, as well as Genoese mercenaries at São Jorge, between the towns of Leiria and Alcobaça, in central Portugal. The result was a decisive victory for the Portuguese, ruling out Castilian ambitions to the Portuguese throne, ending the 1383–85 Crisis and assuring John's position as King of Portugal.

Portuguese independence was safeguarded and a new dynasty, the House of Aviz, was established. Scattered border confrontations with Castilian troops would persist until the death of John I of Castile in 1390, but these posed no real threat to the new dynasty.

The Military Order of Aviz (Portuguese: Ordem Militar de Avis), known previously to 1910 as the Royal Military Order of Saint Benedict of Aviz (Portuguese: Real Ordem Militar de São Bento de Avis), and before 1789 as the Knights of Saint Benedict of Aviz (Portuguese: Ordem de São Bento de Avis) or Friars of Santa Maria of Évora, is one of the four former ancient Portuguese military orders. It gave its name and coat of arms to the House of Aviz that ruled Portugal between 1385 and 1580. The founding king of House of Aviz, John I of Portugal, was an illegitimate son of a previous king, and thus not a member of his father's Portuguese House of Burgundy; however, John was the grand master of the Order of Aviz, and thus was known as "John of Aviz." Founded in 1146, it is the oldest Portuguese honorific order.

Philippa of Lancaster (Portuguese: Filipa [fiˈlipɐ]; 31 March 1360 – 19 July 1415) was Queen of Portugal from 1387 until 1415 as the wife of King John I. Born into the royal family of England, her marriage secured the Treaty of Windsor and produced several children who became known as the "Illustrious Generation" in Portugal. She was the only Queen of Portugal of English origin.

Beatrice (Portuguese: Beatriz, pronounced [bi.ɐˈtɾiʃ]; 7–13 February 1373 – c. 1420) was the only surviving legitimate child of King Ferdinand I of Portugal and his wife, Leonor Teles. She became Queen consort of Castile by marriage to King John I of Castile. Following her father's death without a legitimate male heir, she claimed the Portuguese throne but lost her claim to her uncle, who became King John I of Portugal, founder of the House of Aviz.

During her early years, Beatrice was a pawn in the changing politics of foreign alliances of her father, who negotiated successive marriages for her. She would eventually marry King John I of Castile, by whom Beatrice became Queen Consort of Castile. At the death of her father, Beatrice was proclaimed Queen regnant of Portugal and her mother assumed the regency in her name. Opposition to the regency, fear of the Castilian domination and loss of Portuguese independence led to a popular rebellion and civil war between the late King Ferdinand I's illegitimate brother, John of Aviz, who wrested control of the regency from the dowager queen, and the supporters of Beatrice and her husband, John I of Castile, who claimed the throne of Portugal by right of his wife. In 1385, John of Aviz was proclaimed King of Portugal, and the King of Castile was definitively defeated in the Battle of Aljubarrota, effectively ending any prospects for Beatrice and her husband to assert their rights to the Portuguese crown.