Port wine originated in Portugal's Douro Valley during the late 17th century. British merchants, seeking alternatives to French wines during periods of conflict, began adding brandy to Portuguese wines to stabilize them for shipping.
The Douro Valley became the world's first legally demarcated wine region in 1756 when the Marquis of Pombal established regulations to protect Port's quality and authenticity. The unique terroir of schist soil terraces and steep riverbanks created ideal conditions for growing the traditional Portuguese grape varieties used in Port production.