Public opinion first became a major force in Europe in the period of the French Revolution and of the Restoration. First of all the revolutionaries carried their gospel all over Europe. Later the opponents of French hegemony carried on the war against Napoleon through the press as well as on the battlefield. When peace returned again to Europe in 1814–15 the traditional rulers found that the tempest could not be stilled. Through the press and through the societies open and secret the struggle between the old and the new worlds went on. The old world was powerful and resourceful, but it could never strangle the demon of change. The ferment was European. Philhellenism, which appealed to the classical background of educated Europeans, aimed at aiding the Greek patriots; it also aroused the question why the fight against the oppressor should be limited to the shores of the Aegean. Daniel O'Connell's Catholic Association won the vote for Catholic Ireland from Protestant England; it was admired and copied by Catholic Belgium for use against Protestant Holland. The press became more and more the vehicle of political and of economic change, and the chief means of expression of a middle class avid for political and for economic power.

As opinion in all European countries grew more confident and more vocal, so did the activity of government in controlling it increase. Napoleon saw the importance of this; so did Metternich. Even in liberal countries like England and Restoration France governments showed great activity. For if this was the period of revolution and of the clamant popular will, it was also the period of growing state power.