1. Austria-Hungary: After the war, the Austro-Hungarian Empire was dissolved, and several independent countries were formed in its place. These included Austria, Hungary, Czechoslovakia, and Yugoslavia.
2. Germany: After the war, Germany lost several territories. Alsace-Lorraine was returned to France, North Schleswig was ceded to Denmark, and West Prussia and Posen were given to Poland.
3. Ottoman Empire: The Ottoman Empire, which had controlled much of the Middle East and North Africa before the war, was dismantled. New countries such as Turkey, Iraq, Syria, Lebanon, and Saudi Arabia were created from its former territories.
4. Russia: After the war, the Russian Empire collapsed and was replaced by the Soviet Union. The Soviet Union included Russia, Ukraine, Belarus, Moldova, Georgia, Armenia, and Azerbaijan.
5. Yugoslavia: Yugoslavia was formed after the war by uniting the kingdoms of Serbia, Croatia, Slovenia, Bosnia and Herzegovina, and Montenegro. In the 1990s, Yugoslavia broke up into six independent countries: Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Serbia, and the Republic of North Macedonia.