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.
However, the Swedes began to resent the monopoly trading position of the Hansa (mostly consisting of German citizens), and to resent the income they felt they lost to the Hansa. Consequently, when Gustav Vasa or Gustav I broke the monopoly power of the Hanseatic League he was regarded as a hero by the Swedish people. History now views Gustav I as the father of the modern Swedish nation. The foundations laid by Gustav would take time to develop. Furthermore, when Sweden did develop, freed itself from the Hanseatic League, and entered its golden era, the fact that the peasantry had traditionally been free meant that more of the economic benefits flowed back to them rather than going to a feudal landowning class.
The end of the 16th century was marked by a final phase of rivalry between the remaining Catholics and the new Protestant communities. In 1592, Gustav Vasa’s Catholic grandson and king of Poland, Sigismund, ascended the Swedish throne. He pursued to strengthen Rome‘s influence by initiating Counter-Reformation and created a dual monarchy, which temporarily became known as the Polish-Swedish Union. His despotic rule, strongly characterized by intolerance towards the Protestants, sparked a civil war that plunged Sweden into poverty. In opposition, Sigismund’s uncle and successor, Charles Vasa, summoned the Uppsala Synod in 1593 which officially confirmed the modern Church of Sweden as Lutheran. Following his deposition in 1599, Sigismund attempted to reclaim the throne at every expense and hostilities between Poland and Sweden continued for the next one hundred years.
During the 17th century, Sweden emerged as a European great power. Before the emergence of the Swedish Empire, Sweden was a poor and scarcely populated country on the fringe of European civilisation, with no significant power or reputation. Sweden rose to prominence on a continental scale during the tenure of king Gustavus Adolphus, seizing territories from Russia and Poland–Lithuania in multiple conflicts, including the Thirty Years’ War.