Port is a Portuguese fortified wine from the Douro Valley in the northern provinces of Portugal. Port takes its name from the city of Oporto that is situated at the mouth of the 560-mile long Rio Douro or River of Gold. There is strict usage of the terms Port or Porto which refers only to wines produced in Portugal.
Until the 17th century, French wines were infinitely more popular in Britain than wines from Portugal. However the relationship between France and Britain was quickly deteriorating and as a consequence the British government decided to impose an import tax on French wine. In 1703 the British and Portuguese signed the Methuen Treaty which guaranteed Portugal would buy English cloth in exchange for wine exports. This sealed the relationship between the two countries and wine production in Portugal expanded rapidly.
