Before the end of the year 1625, and within three months after Ferdinand II. had commissioned Wallenstein to raise an army, the latter marched into Saxony at the head of 30,000 men. No important operations were undertaken during the winter: Christian IV. and Mansfeld had their separate quarters on the one side, Tilly and Wallenstein on the other, and the four armies devoured the substance of the lands where they were encamped. In April, 1626, Mansfeld marched against Wallenstein, to prevent him from uniting with Tilly. The two armies met at the bridge of the Elbe, at Dessau, and fought desperately: Mansfeld was defeated, driven into Brandenburg, and then took his way through Silesia towards Hungary, with the intention of forming an alliance with Bethlen Gabor. Wallenstein followed by forced marches, and compelled Gabor to make peace with the Emperor: Mansfeld disbanded his troops and set out for Venice, where he meant to embark for England. But he was already worn out by the hardships of his campaigns, and died on the way, in Dalmatia, in November, 1626, 45 years of age. A few months afterwards Prince Christian of Brunswick also died, and the Protestant cause was left without any native German leader. [Sidenote: 1628.] During the same year the cause received a second and severer blow. On the 26th of August Christian IV. and Tilly came together at Lutter, a little town on the northern edge of the Hartz, and the army of the former was cut to pieces, himself barely escaping with his life. There seemed, now, to be no further hope for the Protestants: Christian IV. retreated to Holstein, the Elector of Brandenburg gave up his connection with the Union of the Saxon States, the Dukes of Mecklenburg were powerless, and Maurice of Hesse was compelled by the Emperor to abdicate. New measures in Bohemia and Austria foreshadowed the probable fate of Germany: the remaining Protestants in those two countries, including a large majority of the Austrian nobles, were made Catholics by force. In the summer of 1627 Wallenstein again marched northward with an army reorganized and recruited to 40,000 men. John George of Saxony, who tried to maintain a selfish and cowardly neutrality, now saw his land overrun, and himself at the mercy of the conqueror. Brandenburg was subjected to the same fate; the two Mecklenburg duchies were seized as the booty of the Empire; and Wallenstein, marching on without opposition, plundered and wasted Holstein, Jutland and Pomerania. In 1628 the Emperor bestowed Mecklenburg upon him: he gave himself the title of "Admiral of the Baltic and the Ocean," and drew up a plan for creating a navy out of the vessels of the Hanseatic League, and conquering Holland for the house of Hapsburg. After this should have been accomplished, his next project was to form an alliance with Poland against Denmark and Sweden, the only remaining Protestant powers.