The Battle of Hemmingstedt took place on February 17th 1500 near the village of Hemmingstedt in present-day Schleswig-Holstein in Germany. It was an attempt of the dukes of Holstein and Schleswig, Duke Friedrich and Duke Johann to subdue the peasantry of Dithmarschen who had established a peasants' republic at the coast of the North Sea. (Duke Johann was at the time also king of the Kalmar Union.)

The ducal army consisted of the "Black Guard", 4.000 mercenaries from the Netherlands, commanded by a petty noble (Junker) named Slentz, 2.000 armoured cavaliers and 5.000 commoners. The defenders were about 3.000 men, all of them peasants. These men were a well-armed, well-organized milita, not the desperate, badly-armed rabble one would associate with the term "peasant rebel". After seizing the village of Meldorf the ducal army advanced, but was stopped at a barricade. The defenders opened at least one dike sluice in order to flood the land. The land quickly turned into morass and shallow lakes. Crammed together on a narrow road with no solid ground on which to deploy, the ducal army was unable to make use of its numerical superiority. The lightly-equipped peasants were familiar with the land and used poles to leap over the ditches. Most of the ducal soldiers were not killed by enemy arms, but drowned.

The farmer Wulf Isebrand was the leader and organiser of the peasants' defence. While he was a real person, the existence of other participants of the battle is not proven. For instance, the legendary Reimer von Wiemerstedt is said to have killed Junker Slentz, the chief of the "Black Guard"; another doubtful participant was the "virgin" Telse.

Many details about the battle were made up later in order to heroize the defenders. In 1900 a pompous monument to the defenders was raised. The cult reached its peak in the Nazi era, when local party members misused the names of the battle participants for their propaganda. Today there is a more neutral museum at the site commemorating the battle.

The Battle of Hemmingstedt is a prime example of the use of terrain in military tactics.