It has been said that during the time of the Kalmar Union the true power around the Baltic Sea was not held by the King of the Union or local nobles, but by the Hanseatic League, or Hansa.

The Hansa was a confederation of powerful merchants founded in Lubeck, Germany that controlled all trade to and from the Baltic. Previous to the league’s rise to power Scandinavia controlled trade around the Baltic, and this lead to much competition between the league and the Kalmar Union. 

The league held such power that it functioned almost as an independent country. Between 1361-1370 league cities waged war against Denmark, sacking Copenhagen and Helsingborg and ultimately forcing the kings of Denmark and Norway to grant the league 15% of their trade profits. 

As the league began to lose power in the 16th century it opened up the Baltic and gave Denmark and Sweden greater significance in Northern European politics as control of Baltic trade fell back into the hands of Denmark-Norway and the quickly growing Swedish Empire.

The Battle of Brunkeberg was fought between Danish and Swedish forces on October 10 1471, a major battle of the Northern Seven years War.

Swedish forces were lead by Sten Sture the Elder, recently elected Viceroy of Sweden and an advocate of secession from the Kalmar Union, who stood against the forces of the Danish king Christian I. During the battle Christian I was injured severely enough to force his retirement from battle. The battle ended in a victory for Swedish forces.

To celebrate his victory, Sten Sture commissioned a statue of Saint George and the Dragon to be placed at Stockholm’s Storkykan church.

The Kalmar Union was created by Queen Margaret I of Denmark, who married King Haakon VI of Norway. Their son Olav became heir to both Denmark and Norway, creating a personal union between the two countries. Unfortunately, Olav died before he was old enough to ascend the throne, and Margaret was made regent of both kingdoms in his stead in 1388-1389. 

Margaret was also elected regent of some parts of Sweden and in 1389 her combined Danish and Swedish troops defeated the Swedish king, Albert of Mecklenberg, securing control over Sweden. Margaret’s grand-nephew Erick, already king of Norway, succeeded the thrones of Denmark and Sweden in 1396.

The union was formalized in 1397 with the Treaty of Kalmar, which outlined an eternal union between the three countries under one king, though the countries were to be governed separately.