Austria-Hungary was a large empire in Central Europe that existed from 1867 to 1918. It was made up of two main parts: Austria and Hungary, each with its own government but united under a single monarch. The empire was home to many different ethnic groups, including Czechs, Slovaks, Croats, and Serbs, which often led to tensions and conflicts. The empire played a significant role in European history, especially during World War I. Its complex political structure and diverse population contributed to its challenges. After the war, Austria-Hungary dissolved, leading to the creation of several new countries, including Czechoslovakia and Yugoslavia.