British-Portuguese relations are foreign relations between Portugal and the United Kingdom. The relationship, largely driven by the nations' common interests as maritime countries on the edge of Europe and close to larger continental neighbours, dates back to the Middle Ages in 1373 with the Anglo-Portuguese Alliance. The two countries now enjoy a friendly and close relationship.
The history of the relationship between Portugal and Britain dates back to the Middle Ages. English Crusaders aided Portugal in the Reconquista, and after taking Lisbon in 1147, the first King of Portugal Afonso Henriques made the Englishman Gilbert of Hastings the Bishop of Lisbon. In 1373 the Kingdom of England signed the Anglo-Portuguese Alliance, the oldest alliance in the world still in force. The alliance was formalised by the Treaty of Windsor in 1386, and in 1387 Philippa of Lancaster, the daughter of John of Gaunt, 1st Duke of Lancaster, was married to John I of Portugal.
During the late 16th century England found itself fighting against Spain which at this time was in personal union with Portugal. The English Armada was launched as part of this conflict in an attempt to restore Portuguese independence and counter both Spanish and Portuguese military ships which formed the Spanish Armada.
A further marriage between the Portuguese and English royal families occurred with the Marriage Treaty in 1662 when Charles II of England married Catherine of Braganza, daughter of King John IV of Portugal. Her dowry gave Britain Tangiers and Bombay, plus free trade to Portuguese colonies in Brazil and Asia. In return Charles raised a brigade of troops to serve in Portugal's Restoration War against Spain. Catherine is credited with popularising tea, which is now seen as a key part of British culture. In 1703, Portugal joined an alliance of England and the Netherlands in the War of the Spanish Succession against France and Spain. That same year, Portugal and England signed the Methuen Treaty. In the 18th century, the two nations were allies in the Seven Years' War.
The 19th century saw the alliance between Portugal and the United Kingdom come into effect once more when Napoleon Bonaparte built the Continental System, which Portugal refused to join, leading Napoleon to invade. In 1807 Napoleon's army attacked Lisbon, forcing the Portuguese royal family to flee to Brazil under the protection of the British Royal Navy. In the later half of the century, as Portugal's imperial power declined following Brazil's independence, there were disputes between itself and the United Kingdom in southern Africa (1890 British Ultimatum) which was a great embarrassment for the Portuguese monarchy and colonial prestige. Portugal was one of the Allies of World War I along with Britain. While officially neutral in World War II, Portugal remained friendly to the British, a counterpart to Spain's cooperation with the Axis.
Portugal was an official Allied Power in World War I; Portuguese troops were the first to be gassed by German soldiers, yet they received nothing after the Treaty of Versailles. In World War II, Prime Minister António de Oliveira Salazar was committed to the six-century-old treaty (which had been renewed in 1899). Portugal provided assistance not by declaring war but by helping Spain stay neutral and by assuming a co-belligerent status against Germany by leasing air bases in the Azores to the Allies in 1943. It cut off vital shipments of tungsten to Germany in 1944, after heavy Allied pressure. Lisbon was the base for International Red Cross operations aiding Allied POWs, and a main air transit point between Britain and the U.S.
The states are members of NATO and Organization for Security and Co-operation in Europe. There have been several state visits between the nations.
The list below is of British and Portuguese town twinnings.