Nor must we forget that there was one moral consideration which worked on the side of Ferdinand. The terrible danger to which Europe was exposed by the Turkish invader was not really removed until the latter part of the seventeenth century; and even Vienna itself was to be once more endangered, before the barbarian could be induced to settle down peaceably beside his neighbours, and confine himself to the oppression of his Christian subjects. When, therefore, Ferdinand found that the local assemblies of the different provinces grudged him their help in this important struggle, and that even at Prague he had difficulty in obtaining both money and soldiers, it was not unnatural that he should feel a growing indifference to liberties which seemed to him so dangerous to the peace and order of Europe. So when in 1555 he had summoned representatives from all his dominions to meet at Vienna, to devise a common scheme of action against the Turk, he must have bitterly resented the absence of the Bohemians, who refused to attend an Assembly where they might be swamped by Germans and Hungarians. An even more fatal point of opposition between the National desire for peace and independence, and the Imperial scheme for the defence of Europe, was found in the question of military organisation. The old privilege of the Bohemians, to refuse their services for foreign wars, was continually insisted on by them in opposition to Ferdinand; and he was almost unavoidably compelled to raise armies which should be independent of national sentiment, and to garrison the frontier towns of Moravia with soldiers drawn from all parts of his dominions.