The Treaty of Windsor is a diplomatic alliance signed between Portugal and England on 9 May 1386 in Windsor and sealed by the marriage of King John I of Portugal (House of Aviz) to Philippa of Lancaster, daughter of John of Gaunt, 1st Duke of Lancaster.[1] With the victory at the Battle of Aljubarrota, 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.[1] The Treaty of Windsor established a pact of mutual support between the countries.[1]
| Treaty of peace, friendship and confederation between John I of Portugal and Richard II, King of England | |
|---|---|
 Treaty of Windsor | |
| Drafted | 9 May 1386 |
| Signed | 24 February 1387 |
| Location | Westminster |
| Negotiators |
|
| Signatories | |
| Ratifiers | |
| Depositary | Portuguese National Archives |
| Language | Latin |
This document is preserved at the Portuguese National Archives.[2]
Historian Matthew Winslett says, "This treaty has been the cornerstone of both nations' relations with each other ever since."[3]
Enduring to this day, the Treaty of Windsor holds the record as the longest-lasting diplomatic treaty in recorded history.[4]
See also
- Anglo-Portuguese Treaty of 1373
- British Ultimatum of 1890 – British diplomatic ultimatum to Portugal regarding Portugal's claims in Africa
- Timeline of Portuguese history
- Anglo-Portuguese Alliance – 1386 alliance between the UK and Portugal
- Treaty of Tagilde – Anglo-Portuguese treaty signed in 1372
- Operation Alacrity
References
Bibliography
- Country profile of Portugal, Archived 31 July 2003 at the Wayback Machine Foreign, Commonwealth and Development Office website
- Livermore, H.V (1947). A History of Portugal. Cambridge University Press. p. 179. Retrieved 7 October 2021.
- Winslett, Matthew (August 2008). The Nadir of Alliance: The British Ultimatum of 1890 and Its Place in Anglo-Portuguese Relations, 1147–1945 (PDF) (MA). Supervising Professor: Douglas Richmond. The University of Texas at Arlington. p. 14. Archived from the original on 17 September 2008. Retrieved 7 October 2021.
