When Maurice's preparations were accomplished, he published a manifesto containing his reasons for taking arms against the Emperor, namely, that he might secure the Protestant religion, which was threatened with immediate destruction; that he might maintain the laws and constitution of the empire; that he might deliver the Landgrave of Hesse from the miseries of a long and unjust imprisonment. By the first proposal he roused all the friends of the Reformation to support him, who had been rendered desperate by oppression. By the second he interested all the friends of liberty in his cause-Catholics no less than Protestants. By the third he drew to his standard all the sympathy which had been universally excited by the Landgrave's unjust imprisonment, and by the rigor of the Emperor's proceedings against him. At the same time Henry of France issued a manifesto, in which he assumed the extraordinary title of "Protector of the liberties of Germany, and of its Captive Princes."
The Emperor, as we have seen, was reposing at Innspruck, within three days' journey of Trent, and narrowly watching the proceedings of the council now sitting there. Maurice, still concealing his designs under the veil of the most exquisite address, despatched a trusted messenger to assure the Emperor that he would wait upon him in a few days at Innspruck; for which friendly visit the Emperor was in daily expectation. But the time for action was now come. The trumpet of war was sounded; and with a well-appointed army of twenty thousand foot and five thousand horse, Maurice pushed on by secret and forced marches, determined to surprise the Emperor and seize his person. The imperial garrisons, by the way, offered no resistance, but tidings reached the imperial quarters, that all Germany had risen, and was in full march upon Innspruck.