Anglo-Portuguese Alliance

Anglo-Portuguese relations

United Kingdom	Portugal

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The Anglo-Portuguese Alliance (or Aliança Luso-Inglesa, "Luso-English Alliance") is the oldest^[1] alliance that is still in force by political bilateral agreement.^[2] It was established by the Treaty of Windsor in 1386, between the Kingdom of England (since succeeded by the United Kingdom) and the Kingdom of Portugal (now the Portuguese Republic), though the countries were previously allied via the Anglo-Portuguese Treaty of 1373.

Since the signing of the Treaty of Windsor, the Kingdom of Portugal and the Kingdom of England, and later the modern Portuguese Republic and United Kingdom, have never waged war against each other, nor have they participated in wars on opposite sides as independent states (with one brief exception as described below). While Portugal was subsumed under the Iberian Union, rebellious Portuguese factions and government in exile sought refuge and help in England. England spearheaded the Anglo-Spanish War (1585–1604) on the side of the deposed Portuguese royal house.

The alliance has served both countries throughout their respective military histories, influencing the participation of the United Kingdom in the Peninsular War, the UK's major land contribution to the Napoleonic Wars and the establishment of an Anglo-American base in Portugal. Portugal aided England (and later the UK) in times of need, for example, in the First World War. Today, Portugal and the United Kingdom are both part of NATO.