e; consequently real power was held for long periods by regents (notably those of the Sture family) chosen by the Swedish parliament. King Christian II of Denmark, who asserted his claim to Sweden by force of arms, ordered a massacre in 1520 of Swedish nobles at Stockholm. This came to be known as the "Stockholm blood bath" and stirred the Swedish nobility to new resistance and, on 6 June (now Sweden's national holiday) in 1523, they made Gustav Vasa their king. This is sometimes considered as the foundation of modern Sweden. Shortly afterwards he rejected Catholicism and led Sweden into the Protestant Reformation. Economically, Gustav Vasa broke the monopoly of the Hanseatic League over Swedish Baltic Sea trade.
The Hanseatic League had been officially formed at Lübeck on the sea coast of Northern Germany in 1356. The Hanseatic 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. 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, Sweden and soon came to dominate the economic life of that city and made the port city of Stockholm into the leading commercial and industrial city of Sweden. Under the Hanseatic trade 2/3rds of Stockholm's imports consisted of textiles and 1/3 of salt. Exports from Sweden consisted of iron and copper.
However, the Swedes began to resent the monopoly trading position of the Hansa (mostly 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 to the
