Hessian War died out, and peaked after 1645 in the Hessian War proper. This open warfare began with the Siege of Marburg in 1645 and ended in April 1648 (but before the Treaty of Westphalia which was concluded later that year and ended the Thirty Years' War) with victory going to Hesse-Cassel. In the aftermath, Upper Hesse was divided and parts of its territory went to the now stronger Hesse-Cassel. At a European level the Hessian War must be viewed in the larger context of the Thirty Years' War, in which the reformed Hesse-Cassel sided with the Protestant Swedish party, whilst Hesse-Darmstadt,
Treaty of Stettin (1653) Pomerania became Brandenburgian Pomerania. During the war, Sweden had occupied the Duchy of Pomerania in 1630. The last Griffin duke Bogislaw XIV died in 1637, his duchy was supposed to be inherited by Brandenburg, who based her claims on in the Treaty of Grimnitz. This however was hindered by the Swedish presence. The 1648 Peace of Westphalia ended the war, and Pomerania was to be partitioned between Brandenburg and Sweden. The 1650 Treaty of Nuremberg roughly defined the areas that should be under control of Sweden and Brandenburg, respectively. The precise border was drawn in the 1653 Treaty of Stettin,