The region has Portugal's highest wine classification as a Denominação de Origem Controlada (DOC) and is registered as a Protected Designation of Origin under EU and UK law, and as a Geographical Indication in several other countries through bilateral agreements.

Alto Douro was one of the 13 regions of continental Portugal identified by geographer Amorim Girão, in a study published between 1927 and 1930.

The person credited with creating the first ambitious Douro wine is Fernando Nicolau de Almeida, who worked as an oenologist with the Port house Ferreira.

He visited Bordeaux during World War II, which gave him inspiration for creating a top-quality table wine.

The wine Barca Velha, first produced in 1952 using grapes from Quinta do Vale de Meão situated in the Douro Superior subregion, was the result.

A contributing factor was Portugal's entry into the European Economic Community in 1986, which meant that the Port lodges' monopoly was abolished,[5] thus paving the way for producers in the Douro valley to produce and bottle their own wine - Port or dry Douro wines.

The region is sheltered from Atlantic winds by the Marão and Montemuro mountains and has a continental climate, with hot and dry summers and cold winters.

It is usually subdivided into three subregions, from the west to the east:[7] Terraced vineyards are very common in the Douro region.