In 1559, the ambitious Duke Adolf of Holstein-Gottorf planned to subjugate the independent peasant republic of Dithmarschen in order to expand his sphere of influence and take revenge for a lost battle: In 1500, the Dithmarschen peasants had defeated the Danish king’s feared ‘Black Guard’ in the Battle of Hemmingstedt and subsequently founded a free peasant republic.

Heinrich Rantzau was the first to learn of the Duke’s plan and immediately informed those around him. When the news also reached the Danish king, he joined the campaign so as not to be left empty-handed when the soils were divided. Heinrich’s father took command of the royal and ducal troops and led them to victory over the peasant army.

Heinrich Rantzau wrote a book about this war, which he justified as a just punishment against the “rebellious and arrogant peasants“: the people of Dithmarschen should “finally learn to submit to a true and righteous authority … “

The campaign against Dithmarschen was the only war in which Heinrich Rantzau took part. While wars were being waged in many parts of Europe, Schleswig-Holstein enjoyed peace throughout his entire term of office. He believed that an ‘arduous peace’ was better than a just war.

In his later years, Heinrich Rantzau developed a comprehensive peace plan. In it, he called for Catholics and Protestants to tolerate each other and for kings and princes to resolve their conflicts through negotiation rather than war. This, he believed, would bring lasting peace to the whole of Europe. The plan was far-sighted, but it could not be realised.