In May 1471, Sten Sture the Elder had been elected as viceroy of Sweden by the Privy Council. Advocating Swedish secession from the Kalmar Union, Sten had garnered large support. In particular his followers were to be found in Stockholm and in the Bergslagen mining region. The latter region's trading with German cities such as Lübeck often found themselves in conflict with Union's Danish foreign policy. So, the roots of the conflict were primarily economic and political interests.

In response to the election of Sture, Christian I of Denmark sailed to Sweden with a military force, intending to unseat him as viceroy of Sweden. Mooring his ships off Skeppsholmen in Stockholm, he set up camp on Brunkebergsåsen, a ridge a short distance north of Stockholm. On Thursday 10 October, Sten Sture lead his troops north to the area near Brunkeberg after which the battle was named. In the ensuing battle, Christian was hit in the face by musket fire. Losing several teeth, he was forced to retire from battle.

The decisive turn of battle in favor of Sture's side occurred when his troops broke out of the forest north of the ridge, as well as attacking from the city. This cut off a contingent of Danish troops at the Klara monastery north of the town. Christian troops retired, however Sten's troops destroyed the makeshift bridge Christian's troops had built, causing many to drown. The battle ended in a victory for Sten Sture. The effect of their struggle was that the foundation for the independent kingdom of Sweden was laid.