The Treaty of Windsor is the diplomatic alliance signed between Portugal and England on 9 May 1386 at
Windsor and sealed by the marriage of King
John I of Portugal
John I ( pt, João uˈɐ̃w̃ 11 April 1357 – 14 August 1433), also called John of Aviz, was King of Portugal from 1385 until his death in 1433. He is recognized chiefly for his role in Portugal's victory in a succession war with Casti ...
(
House of Aviz) to
Philippa of Lancaster, daughter of
John of Gaunt, 1st Duke of Lancaster.
With the victory at the
Battle of Aljubarrota
The Battle of Aljubarrota (; see 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 general Nuno Álvares Pereira, with the support of Englis ...
, assisted by English archers, John I was recognised as the undisputed King of Portugal, putting an end to the ''
interregnum'' of the
1383–1385 Crisis.
The Treaty of Windsor established a pact of mutual support between the countries.
This document is preserved at the
Portuguese National Archives.
Historian Matthew Winslett says, "This treaty has been the cornerstone of both nations' relations with each other ever since."
See also
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Anglo-Portuguese Treaty of 1373
*
British Ultimatum of 1890
The 1890 British Ultimatum was an ultimatum by the British government delivered on 11 January 1890 to the Kingdom of Portugal. The ultimatum forced the retreat of Portuguese military forces from areas which had been claimed by Portugal on the ba ...
*
Timeline of Portuguese history
__NOTOC__
This is a timeline of Portuguese history, comprising important legal and territorial changes and political events in Portugal and its predecessor states. To read about the background to these events, see History of Portugal.
Centuri ...
*
Anglo-Portuguese Alliance
*
Treaty of Tagilde
References
Bibliography
Country profile of Portugal Foreign, Commonwealth and Development Office website
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*
History of Berkshire
Windsor 1386
Windsor 1386
Windsor, Berkshire
14th century in Portugal
1386 in England
Windsor
England–Portugal relations
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