War was actually opened neither by Emperor nor princes, but by the Protestant towns. The capable _condottiere_ Sebastian Schartlin von Burtenbach led the forces of Augsburg and Ulm briskly southward, seized Fussen in the Bishop of Augsburg's territory on July 9th, and then surprised the small force guarding the pass of Ehrenberg, which gave access to the Inn valley. The religious character of the war was emphasized by plunder of churches and ill usage of monks and clergy. Two obvious courses were now open to the insurgent princes. Either they could march direct on Regensburg, where a mere handful of troops protected Charles from a strongly Protestant population, or in support of Schartlin they could clear Tyrol of imperialists, close the passes to Spanish and Italian reenforcements, and even pay a domiciliary visit to the Council of Trent. This latter was Schartlin's programme; the Tyrolese had Protestant sympathies and dreaded the advent of the foreign troops; Charles averred that even their government was ill-affected. Schartlin would even have persuaded the Venetians and Grisons to forbid passage to the Emperor's troops, and have enlisted the services of Ercole of Ferrara, the enemy of the Pope. But either of the two strategic movements was too bold for the Smalkaldic council of war. The first would have violated the neutrality of Bavaria, in which the league still believed, while it had no quarrel with Ferdinand, who was ostensibly conciliatory. The towns, moreover, wished to keep their captain within hail, for they feared the possibility of attack either from Regensburg or from Ferdinand's paltry forces in the Vorarlberg. Schartlin retired on Augsburg, but on July 20th, reenforced by a Wuertemberg contingent, occupied Donauworth, and was here joined on August 4th by the Elector and Landgrave. The insurgent army now numbered fifty thousand foot and seven thousand horse. The very size of this force, by far the largest that Germany could remember, is a disproof of the not uncommon assertion that Charles took the Lutherans by surprise.