Notwithstanding the death of their great king and commander, the Swedes did not withdraw from the war. Hence the struggle went on, the advantage being for the most part with the Protestant allies. Ferdinand, at just this time, was embarrassed by the suspicious movements of his general Wallenstein. Becoming convinced that he was meditating the betrayal of the Imperial cause, the emperor caused him to be assassinated (1634). This event marks very nearly the end of the Swedish period of the war.
The Swedish-French Period (1635–1648).—Had it not been for the selfish and ambitious interference of France, the woeful war which had now desolated Germany for half a century might here have come to an end, for both sides were weary of it and ready for negotiations of peace. But Richelieu was not willing that the war should end until the House of Austria was thoroughly crippled. Accordingly he encouraged Oxenstiern, the Swedish chancellor, to persevere in carrying on the war, promising him the aid of the French armies.
The war thus lost in large part its original character of a contest between the Catholic and the Protestant princes of Germany, and became a political struggle between the House of Austria and the House of Bourbon, in which the former was fighting for existence, the latter for national aggrandizement.
The Treaty of Westphalia (1648).—And so the miserable war dragged on. The earlier actors in the drama at length passed from the scene, but their parts were carried on by others. The year 1643, which marks the death of Richelieu, heard the first whisperings of peace. Everybody was inexpressibly weary of the war, and longed for the cessation of its horrors, yet each one wanted peace on terms advantageous to himself. The arrangement of the articles of peace was a matter of immense difficulty; for the affairs and boundaries of the states of Central Europe were in almost hopeless confusion. After five years of memorable discussion and negotiation, the articles of the celebrated Treaty of Westphalia, as it was called, were signed by the different European powers.
