The Battle of Hemmingstedt took place on February 17, 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.