Common name (also British Association House) for a historically important building in Gregorian style in the Portuguese port city of Porto. It was occupied in 1790 by British port wine trading houses under Consul John Whitehead (a predecessor building built in 1727 stood elsewhere). It is the only "factorei" still in existence, where once "factors" (trade commissioners) negotiated and concluded their deals on foreign territory. The British wine merchants who regularly met in the Faktorei had a decisive influence on the business of port wine. The foundation stone for the port wine boom was laid by the treaty known as the Methuen Treaty, which was concluded as early as 1703 and which provided special customs concessions for the import of Portuguese wines into England. The British subsequently gained an absolute monopoly for the port wine trade.