From that moment the character of the Thirty Years’ War profoundly alters. It is no longer a war of religion, to set limits to the progress of the Counter-Reformation or to save Catholicism or Protestantism from extinction. It is no longer a war of institutions, to maintain the authority of the Emperor or to preserve the sovereign rights of the princes. It is no longer a war of property, to resist the undoing of the territorial settlement of 1555. It is no longer a war for the re-settlement of Germany upon a new basis by military force. German interests no longer have a place in this terrible war waged for the destruction of Germany on German soil. Primarily, it is a war between the House of Bourbon and the House of Habsburg, to break the power of Spain and increase that of France, through the acquisition by the latter of Alsace and Lorraine. Secondarily, it is a war between the Swedes and the Empire, to gain for the former out of German soil an adequate compensation for the money which they had spent and the blood which they had shed. Two points of interest alone remain in tracing the melancholy story of the weary years, the gradual development of the power of France, and the brilliant achievements of skilful generalship. The entrance of France into the war did not at first check the tide of imperialist success. Richelieu overestimated the resources and the military strength of France. [Sidenote: =Unsuccessful campaigns on the frontiers of France, 1635–1637.=] He put into the field no less than four armies, amounting in the aggregate to 120,000 men; but unaccustomed to war, ill disciplined, ill fed, ill paid, and badly commanded, they were no match for the veterans of Spain and the Emperor. It was the first time that the new monarchy in France had made war upon a grand scale, and it had to buy its experience. The campaigns of the years 1635, 1636, and 1637 told a story of almost unrelieved failure. In Italy the French armies just managed to hold their own. In Alsace and the Netherlands they were everywhere out-generalled and beaten back. In 1636, a Spanish army actually invaded France and threatened Paris. Had it not been for the skilful generalship of Bernhard of Saxe-Weimar in the Rhineland, and the signal success which attended the efforts of the Swedish army, it is not at all improbable that the Emperor would have been able to impose upon all Germany the conditions of the peace of Prague, and by procuring the retirement of the Swedes have narrowed the issues involved to the simple one of a national war between France and Austro-Spain. Already Bavaria and Catholic Germany, as well as Saxony, Brandenburg and nearly all the Lutheran powers, had accepted the treaty. Oxenstjerna and the Swedes had refused after protracted negotiations, only because the Emperor and John George would not hear of making over to them an inch of German soil. On their side they would not be content merely with a money indemnity.