Wine, produced in the Douro valley, was already in the 13th century transported to Porto in barcos rabelos (flat sailing vessels). In 1703 the Methuen Treaty established the trade relations between Portugal and England. In 1717, a first English trading post was established in Porto. The production of port wine then gradually passed into the hands of a few English firms. To counter this English dominance, Prime Minister Marquis of Pombal established a Portuguese firm receiving the monopoly of the wines from the Douro valley. He demarcated the region for production of port, to ensure the wine's quality; this was the first attempt to control wine quality and production in Europe. The small winegrowers revolted against his strict policies on Shrove Tuesday, burning down the buildings of this firm. The revolt was called Revolta dos Borrachos (revolt of the drunks).
Between 1732 and 1763, Italian architect Nicolau Nasoni designed a baroque church with a tower that would become its architectural and visual icon: the Torre dos Clérigos (English: Clerics Tower). During the 18th and 19th centuries the city became an important industrial centre and saw its size and population increase