A great and general desire for peace grew as the Thirty Years` War of religious ruins continued unabated. Since war was not decided by a final and final victory that gave either party a decisive victory, it should be ended by peace or compromise, and obviously it should be based on principles other than the religious orthodoxies that had triggered the conflict in the beginning. The war became less a matter of religion than of the continuation of the Franco-Habsburg rivalry for European political supremacy. Sweden, then a great military power, intervened in 1630 under the great general Gustav Adolf and began the great war on the continent. Spain, which finally wanted to crush the Dutch rebels in the Netherlands and the Dutch Republic, intervened under the pretext of helping its habsburg dynastic relative, Austria. As Catholic France was no longer able to tolerate the encirclement of two major Habsburg powers on its borders, it joined the coalition alongside the Protestants to oppose the Habsburgs. Joachim Whaley, a prominent English-speaking historian of the Holy Roman Empire, mentions that later commentators such as Leibniz, Rousseau, Kant and Schiller praised the Peace of Westphalia as the first step towards universal peace, but stresses that “their projections for the future should not be confused with descriptions of reality.” [4] Sweden preferred to negotiate with the Holy Roman Empire in Osnabrück, which was controlled by Protestant forces. Osnabrück was a Bidenominational Lutheran and Catholic city with two Lutheran churches and two Catholic churches. The city council was exclusively Lutheran, and the citizens for the most part, but the city was also home to the Catholic chapter of the Prince-Bishopric of Osnabrück and had many other Catholic inhabitants. Osnabrück was submissive by the troops of the Catholic League from 1628 to 1633, then taken by Lutheran Sweden. Famous commanders include Marshal Turenne and prince de Condé for France, Wallenstein for the Empire and Tilly for the Catholic League, and there was a competent Bavarian general named Franz von Mercy. Others who played a role ranged from the winter king of Bohemia to emperors Ferdinand II and Ferdinand III, Bethlen Gabor of Transylvania, Christian IV of Denmark, Gustavus II Adolphus and Queen Christina of Sweden, the great elector of Brandenburg, Philip IV. Louis XIII of France, the cardinals of Richelieu and Mazarin and several popes.

Gustav Adolf was shot in the head and killed in the head at the Battle of Lutzen in 1632. .