The "Ausgleich" or compromise of February 1867 created the Empire's dualist structure. The Austrian Empire (1804–67) had lessened in strength and in power. This was because of the Austro–Sardinian War of 1859 and the Austro–Prussian War of 1866. Also, the Hungarian people were not happy with how Vienna treated them. This had been going on for many years and it led to Hungarian separation. This included the Hungarian liberal revolution of 1848–49.