For more than a century after the final subjugation of the Prussians in 1283, the Teutonic Knights were the undisputed rulers of a vast and well-organized domain that stretched along the coast of the Baltic Sea, from the river Oder to Leningrad. The grand master, residing in his fortified convent of Marienburg and then from 1457 on at Königsburg, was _de jure et de facto_ a sovereign, equal to the other princes of the Empire, and only nominally subordinate to the Emperor. But in the fifteenth century decline set in. The first blow was struck in 1410, when in the battle of Tannenberg the Knights were overthrown by the Polish troops. In 1525 the Order received the _coup de grâce_; its grand master Albrecht of Brandenburg embraced the Protestant religion, secularized the possessions of the Order in East Prussia which once he had vowed to protect, and styled himself Duke of Prussia.[21] When later this duchy was united with Brandenburg, the foundations were laid for the kingdom of Prussia and eventually for the German Reich of the Hohenzollerns. In 1561, when Gotthard Kettler, “Landmeister” of Livonia, followed Albrecht’s apostasy, the Teutonic Order ceased to be a sovereign power. However, the loss of sovereignty did not mean the end of the Teutonic Order, for—although a skeleton of its former glory—it still possessed large estates and strongholds in Western Germany. (During the Reformation the Teutonic Knights in the Netherlands separated themselves from their Catholic brethren. This Protestant branch was suppressed by Napoleon but was re-established at the time of the Restoration and is known as the bailiwick of Utrecht.) After the loss of Prussia the general head of the order became known as “Hoch-und Deutsch Meister” (Grand-and Teutonic Master). From 1590 on, these grand masters were almost without exception members of the imperial house of Hapsburg, which meant that the former independent Teutonic Order became more and more an appendix of the Austrian crown. Nevertheless, the order was not completely secularized. True, community life soon ceased to exist, but the knights still took religious vows. The next blow was dealt by Napoleon, who suppressed the Teutonic Order in Germany and confiscated its possessions. The order was now restricted to the confines of the Austrian empire. Around 1839, attempts were made to revive the languishing order by dedicating its members—priests and professed knights—to its original objective, namely ambulance service and works of charity. Besides, the professed knights, instead of fighting the infidels, took upon themselves the obligation of serving as officers in the Austrian army. The question of profession was settled by a papal indult in 1886 (_Neminem profecto latet_, March 16, 1886), according to which the knights of the Teutonic Order were to take simple perpetual vows which, however, included the same rights and obligations as solemn vows.