Ottoman Empire in World War I

The Ottoman Empire was one of the Central Powers of World War I, allied with the German Empire, Austria-Hungary, and Bulgaria. It entered the war on 29 October 1914 with a small surprise attack on the Black Sea coast of the Russian Empire, prompting Russia—and its allies, France and Great Britain—to declare war the following month.

World War I had erupted almost exactly three months prior, on 28 July, following a series of interrelated diplomatic and military escalations among the major powers of Europe triggered by the assassination of Archduke Franz Ferdinand, heir presumptive to the Austro-Hungarian throne, by Bosnian Serb nationalist Gavrilo Princip. The Ottoman Empire, which had no stake in the immediate causes and considerations of the conflict, declared neutrality and negotiated with nations on both sides; though regarded by the great powers as the "sick man of Europe" due to its perceived decline and weakness, the empire's geostrategic location and continued influence had nonetheless made it a critical consideration in any potential conflict. Decades of close economic, diplomatic, and military ties with Germany, among other factors, culminated in its decision to enter the war on the side of the German-led Central Powers.

The Ottomans were substantial contributors to the war effort. Though consistently plagued by logistical, technological, and technical limitations, they managed to mobilize over 3 million men, having started the war with only about 210,000. Ottoman forces fought in the Balkans and Middle Eastern theatres of the war, holding down large numbers of Entente troops. They were a leading and decisive participant in the Caucasus, Gallipoli, and Sinai and Palestine campaigns, and dominated the South Caucasus.

The Ottoman Empire's defeat in the war in 1918 was crucial in the eventual dissolution of the empire in 1922.