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Germany
During World War I, the German Empire was one of the Central Powers that lost the war. It began participation in the conflict after the declaration of war against Serbia by its ally, Austria-Hungary. -
Austria-Hungary
Austria-Hungary was a multinational state and one of Europe's major powers at the time. ... Austria-Hungary was one of the Central Powers in World War I which started when it declared war on the Kingdom of Serbia on 28 July 1914 -
Ottoman Empire
The Ottoman Empire participated in World War I as one of the Central Powers. The Ottoman Empire entered the war by carrying out a surprise attack on Russia's Black Sea coast on 29 October 1914, with Russia responding by declaring war on 5 November 1914. -
Bulgaria
The Kingdom of Bulgaria participated in World War I on the side of the Central Powers from 14 October 1915, when the country declared war on Serbia, until 30 September 1918, when the Armistice of Thessalonica came into effect.