Siege of Dorsten

The Siege of Dorsten was a military conflict that lasted from 16 July 1641 to 19 September 1641 during the Thirty Years' War in Europe. The opposing sides were the Landgraviate of Hesse-Cassel and the Holy Roman Empire of the German Nation.

According to a judgement by the Vienna Supreme Court , Hesse-Cassel had to cede Upper Hesse, which included the University of Marburg, to Hesse-Darmstadt. In return for this substantial loss, in the Treaty of Werben on 22 August 1631, King Gustavus Adolphus of Sweden promised to grant the state of Hesse-Cassel, various territories including parts of the Prince-Bishopric of Münster and Vest Recklinghausen if he were victorious in the Thirty Years' War.

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