[5] In the summer of 1380, a combined Spanish-French fleet of 20 galleys under the command of Fernando Sánchez de Tovar departed from Seville to launch a raid on Gravesend.

He ransomed Leo V of the House of Lusignan,[6] the last Latin king of the Armenian Kingdom of Cilicia, from the Mamluks and out of pity granted him the lifetime lordship of Madrid, Villa Real and Andújar in 1383.

[11] The king of Castile finally bought off the claim of his English competitor by arranging a marriage in 1388 between his son Henry and Catherine, daughter of Constance and John of Gaunt,[2][12] as part of the treaty ratified at Bayonne.

Pedro de Luna, a Papal legate to the realms of Castile, Aragon, Portugal and Navarre, pronounced the betrothal in Elvas on 14 May, and the wedding ceremony took place on 17 May at the Cathedral of Badajoz.

King John I then met the Council in Montalbán and sent Alfonso Lopez de Tejada with instructions for the regent, now Queen Mother, to proclaim Beatrice and himself the rulers of Portugal.

[28] John I of Castile assumed the title and coat of arms of King of Portugal, which investiture was recognized by the Pope of Avignon,[29] and ordered the deployment of his troops when the Bishop of Guarda and chancellor to Beatrice, Afonso Correia, promised to deliver the support of the people.

[20] However, the expectation of a Spanish commercial monopoly, fear of Castilian rule and the loss of Portuguese independence, reinforced by popular opposition to the regent and her allies, led to an uprising in Lisbon in late November and early December.

The Master of Aviz, future John I of Portugal, ignited the rebellion when he broke into the royal palace on 6 December 1383 and assassinated Leonor's lover, Conde Andeiro,[32] after which the common people rose up against the government at the instigation of Alvaro Pais.

[35] The uprising spread to the provinces, taking the lives of the abbess of the Benedictine nuns in Évora, the Prior of the Collegiate Church of Guimarães,[36] and Lançarote Pessanha, Admiral of Portugal, who was murdered at the Castle of Beja.

The distinguished jurist João das Regras was appointed as chancellor[40] and the brilliant general Nuno Álvares Pereira as constable;[41] immediately England was requested to intervene.

On 13 January King John I and Queen Beatrice obtained the waiver of the rule and the government in their favour, which caused many knights and castle lords to submit and swear allegiance to the royal couple.

Although most of the Portuguese aristocracy was loyal to his cause, King John I of Castile did not repeat the Castilian successes of the earlier Fernandine Wars (Guerras Fernandinas) and failed to win Coimbra and Lisbon.

In March 1385 he went to Coimbra, to which he had summoned the Portuguese Cortes;[43] they declared Beatrice illegitimate and proclaimed the Master of Aviz to be King of Portugal as John I on 11 April.

Advancing from Santarém, he seized the region north of the Duero whose knights had remained faithful to Beatrice and John I of Castile: Villareal Pavões, Chaves and Bragança capitulated[48] at the end of March 1386, and Almeida in early June 1386.

Queen Beatrice had no children with her husband John I of Castile, although a son called Miguel is mentioned in several genealogies written much later and even in some modern history books.

[50] King John died in Alcalá on 9 October 1390, when he fell from his horse while riding in a fantasia, a traditional display of horsemanship with light horsemen known as farfanes mounted and equipped in the Arab style.