It might seem doubtful whether he would long remain a monarch at all. When in A.D. 1493 the calamitous reign of Frederick the Third ended, it was impossible for the princes to see with unconcern the condition into which their selfishness and turbulence had brought the Empire. The time was indeed critical. Hitherto the Germans had been protected rather by the weakness of their enemies than by their own strength. From France there had been little to fear while the English menaced her on one side and the Burgundian dukes on the other: from England still less while she was torn by the strife of York and Lancaster. But now throughout Western Europe the power of the feudal oligarchies was broken; and its chief countries were being, by the establishment of fixed rules of succession and the absorption of the smaller into the larger principalities, rapidly built up into compact and aggressive military monarchies. Thus Spain became a great state by the union of Castile and Aragon, and the conquest of the Moors of Granada. Thus in England there arose the popular despotism of the Tudors. Thus France, enlarged and consolidated under Lewis the Eleventh and his successors, began to acquire that predominant influence on the politics of Europe which her commanding geographical position, the martial spirit of her people, and, it must be added, the unscrupulous ambition of her rulers, have secured to her in every succeeding century. Meantime there had appeared in the far East a foe still more terrible. The capture of Constantinople gave Turks a firm hold on Europe, and inspired them with the hope of effecting in the fifteenth century what Abderrahman and his Saracens had so nearly effected in the eighth--of establishing the faith of Islam through all the provinces that obeyed the Western as well as the Eastern Cæsars. The navies of the Ottoman Sultans swept the Mediterranean; their well-appointed armies pierced Hungary and threatened Vienna. [Sidenote: Loss of imperial territories.] Nor was it only that formidable enemies had arisen without: the frontiers of Germany herself were exposed by the loss of those adjoining territories which had formerly owned allegiance to the Emperors. Poland, once tributary, had shaken off the yoke at the interregnum, and had recently wrested Prussia and Lusatz from the Teutonic knights. Bohemia, where German culture had struck deeper roots, remained a member of the Empire; but the privileges she had obtained from Charles the Fourth, and the subsequent acquisition of Silesia and Moravia, made her virtually independent. The restless Hungarians avenged their former vassalage to Germany by frequent inroads on her eastern border. [Sidenote: Italy.]