During the course of the negotiations the Forest-cantons remained intractable and warlike. Indeed the final proposals of the mediators would probably have been received by the Protestants, but they were decidedly rejected by the Catholics. Matters were now so much involved that war became inevitable. The preparations of the five cantons being completed, they took the field on the 6th of October, 1531. They were the first in arms. The defense of the church and the holy see were their real objects for waging war, though the interdiction of commerce was the ostensible grievance. The chiefs were closely united together, and the people, burning with indignation against those who had taken away their food, and were seeking to take away their religion, powerfully supported them. Their common faith and sufferings, united them as by one spirit for one object, which could not fail to impart resolution and courage in action. But no alarm had yet been given: Zurich was asleep. All the passes were seized, all communication between Zurich and the five cantons had been rendered impossible. "The terrible avalanche," says our Swiss historian, "was about to slip from the icy summits of the mountain, and to roll over the valleys, even to the gates of Zurich, overthrowing everything in its passage, without the least forewarning of its fall."
In the hope of dividing the Reformed, the Catholics declared war, not against the body of the Reformers, but against Zurich only. The eye of Jezebel was set upon the blood of Zwingle. Whoever may be saved, he must be slain. So long as he lives, there can be no peace for holy mother church in Switzerland. Let the battle be against the arch-heretic. Thus inspired by the papal demon of war, the mountain warriors assembled in their chapels, heard mass, and then, to the number of eight thousand, began their march toward the Protestant frontier. A papal army, twelve thousand strong, marched into the free parishes. The soldiers having entered the deserted churches, and seeing the images and the altars broken down, their anger was kindled to madness. They spread like a torrent over the whole country, inflicting all the horrors of war wherever they came. The country people, terrified, and running from chalet to chalet, calling aloud for help, failed to arouse the bewitched Zurichers; yet in four days was the ruin of Zurich accomplished.