Battle of Hemmingstedt
1500 CE.
Shown on the map at 54.147°, 9.072°.
The Battle of Hemmingstedt occurred on 17 February 1500, south of the village of Hemmingstedt near the present village of Epenwöhrden in the western part of present-day Schleswig-Holstein, Germany. It was an attempt by King John of Denmark and his brother Duke Frederick, who were co-dukes of Schleswig and Holstein to subdue the peasantry of Dithmarschen, who had established a peasants' republic on the coast of the North Sea. John was, at the time, also king of the Kalmar Union.
Text from the Wikipedia article Battle of Hemmingstedt, licensed CC BY-SA 4.0.