Part 2 : The Treaty of Windsor 1386
In 1353 the merchants and mariners of the cosmopolitan port of Lisbon had concluded an unofficial treaty with king Edward III of England which vastly increased Portuguese commerce with northern European countries. At the end of the reign of king Pedro I (the Justicer) in 1367 the chronicler Fernão Lopes reports that as many as 450 trading ships would lie in the Tagus estuary and that 12,000 tuns of wine would pass through in a year. The customs revenues were immense and used in part to benefit a grateful populace while the balance went to the royal coffers held in the Lisbon fortress where 800,000 pieces of gold and 400,000 marks of silver were inherited by the successor king Fernando I (the Inconstant).
During his reign of sixteen years Fernando I dissipated this great wealth through a series of wars, intrigues and reckless adventures which caused a reduction in trade, consequent inflation and much consternation to his subjects. From the outset he was involved in a series of disputes and secret alliances with the monarchies of Léon, Castille and Aragon (all being linked by marriages and liaisons) which were at war with each other when not fighting the Moors on their southern boundaries .
The duplicity of King Fernando 1 in signing treaties of alliance with both Castille and England in 1373 was rewarded by ten years of chaos during which his subjects came close to civil war. The commercial classes vehemently defended continuing national independence while most of the nobility and some of the royal family saw their future in uniting the crowns of Castille and Portugal. For example Fernando´s half brothers , the sons of his father´s affair with Înes de Castro, went to live in Castille , married Castilian princesses and set up a rival form of “government in exile”. Moreover , as Fernando became weaker through sickness, the control of his kingdom passed to his Queen Leonor (Teles de Menezes) and her lover João Andeiro (the new count of Ourem) who were equally expert at playing a double game.
In 1381 Andeiro had revived the terms of the 1373 Treaty by inviting the duke of Cambridge to land in Portugal with 3,000 English soldiers who proved to be untrained, unruly and unkempt. Being unpaid, these mercenaries formed raiding parties which looted towns on both sides of the frontier thus causing great distress to the terrorised citizens and the indignation of the Portuguese middle classes some of whom were of English descent . Eventually, this rabble was brought to heel and, with Portuguese troops, faced the Castilian army near Badajoz/Elvas but battle was not engaged because a secret agreement was reached whereby Fernando´s daughter Beatrix would marry the younger son of king Juan who would arrange for the evacuation of the remaining forces of the angry Cambridge in boats of the Castilian navy. When king Juan became a widower in March 1383 this arrangement was replaced by his decision to take the young Beatrix as his wife and that their first male issue would become king of the two united nations.
Into the breach caused by this morass stepped John of Avis (1357-1433) who was to become defender and king for a reign of 43 years. He was one of the many illegitimate children of Pedro I and received religious and cultural tutelage from the Galician Grand Master of the Order of Christ. On learning of the plan of king Juan of Castile to secure for himself the throne of Portugal he led an insurrection against the authority of Queen Leonor and went with the Master of Santiago to England to raise troops who would fight alongside the forces raised by the youthful Nun`Alvares Pereira in the Alentejo. Despite a small victory at Atoleiros , the superior numbers of the Castilians enabled them to penetrate as far as Lisbon but there they were afflicted by the plague which daily killed several hundred soldiers and caused king Juan to withdraw all of his forces to winter in Seville. This enabled John of Avis to consolidate his position and on 06 April 1384 he was proclaimed as Rei João I and promptly proposed to the English king Richard II a new and stronger alliance. On hearing of this king Juan re-invaded Portuguese territory but after minor skirmishes at Trancoso and Porto de Mós was soundly defeated at the battle of Aljubarrota on 14 August 1385.
This victory led immediately to the assertion by John of Gaunt of his claim by marriage to the Castilian throne and a proposal that joint Portuguese and English armies should launch an attack. To formalise this a much more comprehensive Treaty of Anglo-Portuguese Alliance was concluded at Windsor in May 1386 which was to apply not only to the territory of the two kingdoms but to their citizens wherever they may be – at sea or on land. João I sent a squadron of six galleons to assist a blockade of French seaports while Lancaster arrived at Corunna with an initial force of 5,000 men-at-arms who met a larger number of Portuguese troops at Bragança . But resistance by the castles and towns of Léon was stronger than expected and constable Nun`Alvares , who was not impressed by either Lancaster´s or his troops´ abilities, was forced to withdraw to safer ground.
John of Gaunt thereupon withdrew his claims to the monarchy of Castille in return for the payment of a large indemnity and an agreement that his daughter Catherine should marry the future king Henry III. He then evacuated to Bayonne his depleted expeditionary force in fourteen galleys furnished by his son-in-law king João I who had married his eldest daughter Phillipa the previous year. This left king Joâo I still at war with Castille without the assistance promised in the Windsor Treaty which, nevertheless, he ratified while Portuguese warships continued to serve in the defence of England until the Anglo-French truce agreed in 1389. John of Gaunt played no further part in the peninsular wars being content to enjoy his large pension and income from his many estates.
In Part 3 we shall review the inconsistencies of successive Anglo-Portuguese alliances until modern times.