Pope Alexander VII place in two cities, Osnabrück and Münster in Westphalia, with intermediaries travelling back and forth between the Protestant and the Catholic delegates. Chigi, of course, protested on behalf of the Papacy, when the treaties were finally completed, against the Treaty of Westphalia once the instruments were finally completed. Pope Innocent himself stated that the Peace "is null, void, invalid, unjust, damnable, reprobate, inane, empty of meaning and effect for all time." The Peace ended the Thirty Years' War (1618–1648) and established the balance of European power that lasted until the wars of the French Revolution (1789). Pope Innocent X (1644–1655)
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