Thirty Years' War four-year period, the warring parties (the Holy Roman Empire, France, and Sweden) were actively negotiating at Osnabrück and Münster in Westphalia. The end of the war was not brought about by one treaty, but instead by a group of treaties such as the Treaty of Hamburg. On 15 May 1648, the Peace of Münster was signed, ending the Thirty Years' War. Over five months later, on 24 October, the Treaties of Münster and Osnabrück were signed. The war ranks with the worst famines and plagues as the greatest medical catastrophe in modern European history. Lacking good census information, historians have
Hessian War Peace Congress mediated by Duke Ernest of Saxe-Gotha and which resulted in a unification and peace treaty that was sealed in April 1648, ahead of the Treaty of Westphalia itself. Before the Westphalian Peace Treaty, Cassel fought one last time against the imperial side, winning the Battle of Wevelinghoven in the Rhineland, together with other Protestant troops. Darmstadt, however, was not involved in this battle. Under the Unification Treaty between Cassel and Darmstadt, Upper Hesse was permanently divided. Darmstadt had to give up a significant part of Upper Hesse to Cassel, not least Marburg and other occupied territories, including the