- Treaty of Brest-Litovsk (March 1918): This treaty was signed between Russia and the Central Powers (Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire). It gave the Central Powers control over large areas of Russian territory, including Poland, Ukraine, and the Baltic States.
- Treaty of Bucharest (May 1918): This treaty was signed between Romania and the Central Powers. It forced Romania to cede Bessarabia to Russia and Dobruja to Bulgaria.
- Treaty of Brest-Litovsk (November 1918): This treaty was a revision of the original Treaty of Brest-Litovsk, and it was signed after the Central Powers had defeated Russia in the German spring offensive. It gave the Central Powers even more territory, including the Caucasus and the Ukraine.
- Treaty of Versailles (June 1919): This treaty was signed between Germany and the Allied Powers (France, the United Kingdom, the United States, Italy, and Japan). It was the most important of the peace treaties, and it imposed harsh conditions on Germany, including the loss of territory, reparations, and the disarmament of its military.