Cause:
The fall of Metternich, who had been the champion of despotism and reaction throughout Europe, and the revolutionary spirit which ran through Europe in 1848, created great unrest in the Austro-Hungarian Empire. The Emperor Ferdinand was weak and worthless, and the Magyars were determined not to submit to the domination of autocratic rule in Austria. Jellacic, the Croatian leader, hoped to create a Southern Slav state: he co-operated with the Austrians in opposition to Hungary, and was supported by the Czechs of Bohemia.