AustriaHungary

Austria-Hungary, officially the Austro-Hungarian Empire, was a constitutional union formed in 1867 between the Austrian Empire and the Kingdom of Hungary, creating a dual monarchy under the Habsburgs. The Compromise of 1867 established Cisleithania (the Austrian part) and Transleithania (the Hungarian part), each with its own parliament and government, while recognizing a shared monarch who held the titles of Emperor of Austria and King of Hungary. The empire maintained common ministries for foreign affairs, defense, and finances and a joint army and navy, though most domestic matters were managed separately. Vienna was the imperial capital, while Budapest served as the Hungarian capital. The empire spanned much of Central Europe and was home to a diverse mix of peoples, including Germans, Czechs, Hungarians, Poles, Ukrainians, Romanians, Slovaks, Slovenes, Croats, Serbs, Bosniaks, Italians, and others.

Economically, Austria-Hungary was highly industrialized in the western and central regions, with significant rail and manufacturing networks, though development was uneven and nationalist tensions, language policies, and regional disparities persisted. The empire faced rising nationalist aspirations from various ethnic groups and a complex political environment as it balanced two parliaments with a shared executive structure.

The assassination of Archduke Franz Ferdinand in 1914 precipitated World War I, and the empire fought as part of the Central Powers before collapsing under military defeat and internal dissolution by late 1918. The monarchy was soon replaced by independent states, including Austria and Hungary as republics, and the territories of the former empire were reorganized into nations such as Czechoslovakia, the Kingdom of Serbs, Croats, and Slovenes (later Yugoslavia), and parts of Poland and Romania. Postwar treaties, notably Saint-Germain and Trianon, formalized the new borders.