The Hanseatic League had been officially formed at Lübeck on the Baltic coast of Northern Germany in 1356. The League sought civil and commercial privileges from the princes and royalty of the countries and cities along the coasts of the Baltic Sea. In exchange, they offered a certain amount of protection to the joining cities. Having their own navy, the Hansa were able to sweep the Baltic Sea free of pirates. The privileges obtained by the Hansa included assurances that only Hansa citizens would be allowed to trade from the ports where they were located. They sought agreement to be free of all customs and taxes. With these concessions, Lübeck merchants flocked to Stockholm, where they soon came to dominate the city's economic life and made the port city of Stockholm into the leading commercial and industrial city of Sweden. Under the Hanseatic trade, two-thirds of Stockholm's imports consisted of textiles, while the remaining third was salt. The main exports from Sweden were iron and copper.