Of course, it was by no means obvious in 1815 that a constructive national and international principle had come to dominate the European political system.  The Treaty of Vienna was an unprincipled compromise among the divergent interests and claims of the dominant Powers, and the triumphant monarchs ignored their promises of national reform or representation.  For one whole generation they resolutely suppressed, so far as they were able, every symptom of an insurgent democratic or national idea.  They sought persistently and ingeniously to identify in Europe the principle of political integrity and order with the principle of the legitimate monarchy.  But obscurantist as were the ideas and the policy of the Holy Alliance, the political system it established was an enormous improvement upon that of the eighteenth century.  Not only was the sense of responsibility of the governing classes very much quickened, but the international system was based on a comparatively moral and rational idea.  For the first time in European history a group of rulers, possessing in theory absolute authority and forming an apparently irresistible combination, exercised this power with moderation.  They did not combine, as in the case of the partition of Poland, to break the peace and prey upon a defenseless neighbor, but to keep the peace; and if to keep the peace meant the suppression wherever possible of liberal political ideas, it meant also the renunciation of aggressive foreign policies.  In this way Europe obtained the rest which was necessary after the havoc of the Revolutionary wars, while at the same time the principle on which the Holy Alliance was based was being put to the test of experience.  Such a test it could not stand.  The people of Europe were not content to identify the principle of political order, whether in domestic or foreign affairs, with that of legitimate monarchy and with the arbitrary political alignments of the Treaty of Vienna.  Such a settlement ignored the political forces and ideas which, while originating in Revolutionary France, had none the less saved Europe from the consequences of French Revolutionary and Imperial aggression.

Beginning in 1848, Europe entered upon another period of revolutionary disturbance, which completely destroyed the political system of the Holy Alliance.  At the outset these revolutions were no more respectful of national traditions than was the French Revolution; and as long as they remained chiefly subversive in idea and purpose, they accomplished little.  But after some unsuccessful experimentation, the new revolutionary movement gradually adopted a national programme; and thereafter, its triumphs were many and varied.  For the first time in political history the meaning of the national principle began to be understood; and it became in the most explicit manner a substantial and a formative political idea.