Meanwhile the Emperor Rudolf II. was becoming so old, so whimsical and so useless, that in 1606 the princes of the house of Hapsburg held a meeting, declared him incapable of governing, "on account of occasional imbecilities of mind," and appointed his brother Matthias regent for Austria, Hungary and Moravia. The Emperor refused to yield, but, with the help of the nobility, who were mostly Protestants, Matthias maintained his claim. He was obliged, in return, to grant religious freedom, which so encouraged the oppressed Protestants in Bohemia that they demanded similar rights from the Emperor. In his helpless situation he gave way to the demand, but soon became alarmed at the increase of the heretics, and tried to take back his concession. The Bohemians called Matthias to their assistance, and in 1611 Rudolf lost his remaining kingdom and his favorite residence of Prague. As he looked upon the city for the last time, he cried out: "May the vengeance of God overtake thee, and my curse light on thee and all Bohemia!" In less than a year (on the 20th of January, 1612) he died. Matthias was elected Emperor of Germany, as a matter of course. The house of Hapsburg was now the strongest German power which represented the Church of Rome, and the Catholic majority in the Diet secured to it the Imperial dignity then and thenceforward. The Protestants, however, voted also for Matthias, for the reason that he had already shown a tolerant policy towards their brethren in Austria, Hungary and Bohemia. His first measures, as Emperor, justified this view of his character. He held a Diet at Ratisbon for the purpose of settling the existing differences between the two, but nothing was accomplished: the Protestants, finding that they would be outvoted, withdrew in a body and thus broke up the Diet. Matthias next endeavored to dissolve both the "Union" and the "League," in which he was only partially successful. At the same time his rule in Hungary was menaced by a revolt of the Transylvanian chief, Bethlen Gabor, who was assisted by the Turks: he grew weary of his task, and was easily persuaded by the other princes of his house to adopt his nephew, Duke Ferdinand of Styria, as his successor, in the year 1617, having no children of his own. [Sidenote: 1618. BEGINNING OF THE THIRTY YEARS' WAR.]