The Austro-Hungarian Empire was a dual monarchy in Central Europe that existed from 1867 to 1918. It was formed by the union of the Austrian Empire and the Kingdom of Hungary, creating a complex political structure with two separate governments under one monarch, Emperor Franz Joseph I. The empire included various ethnic groups, leading to diverse cultures and languages. At its height, the Austro-Hungarian Empire encompassed regions that are now part of several countries, including Austria, Hungary, Czech Republic, Slovakia, Croatia, and parts of Italy and Poland. The empire played a significant role in European politics until its dissolution after World War I.