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,
History of the Catholic Church in Germany for predominance in Europe. The war resulted in large areas of Germany being laid waste, a loss of approximately a third of its population, and in a general impoverishment. The war ended in 1648 with the Peace of Westphalia, signed in Münster and Osnabrück: Imperial territory was lost to France and Sweden and the Netherlands left the Holy Roman Empire after having de facto seceded 80 years earlier. The imperial power declined further as the states' rights were increased. "Aided by the personal charm of its young king Louis XIV, who had assumed the government in 1661, France appeared to