Although the revolutions of 1848 were simultaneous and inspired by a common ideology, yet they were isolated phenomena. There was no international revolutionary organisation and the political refugees gathered together in France, Belgium, Switzerland and England were not the instigators of the revolutions in their countries. There was no plot and the revolutions were not concerted. Problems which were analogous in general took different forms in each state and produced conflicting results; the same vocabulary, the same programme, concealed dissimilar situations.

At the beginning of 1848 no one believed that revolution was imminent; yet the situation in many parts of Europe was such as precedes revolutions. In Italy the advent of Pius IX in June 1846, the general amnesty which he declared and the promises which he uttered, had created an atmosphere of wild excitement. There was unrest in Lombardy–Venetia which led to the declaration of a state of siege, there was the Sicilian insurrection of 12 January, and there was the grant or promise during February of constitutions at Turin, Florence and Naples. To a lesser degree a pre-revolutionary situation also existed in France. In the campaign of banquets to demand parliamentary and electoral reform the coalition of opposition parties had allowed the leadership to pass to the republicans, and Guizot's ministry barely survived the debate on the address on 12 February. In Germany liberal and radical party congresses had drawn up definite programmes of reform. In Ireland, general agreement had been reached on a programme of independence, and the supporters of Smith O'Brien and John Mitchel differed only on the means of attaining this end—by political agitation or by resort to force.