1914 - 1917
The War between Russia and Turkey
Enver Pasha (1881-1922) served in the dual capacity of War Minister and Ottoman Commander-in-Chief during World War One, and was instrumental in bringing Turkey into the war on the side of the Central Powers.
On August 2, 1914, Enver concluded a secret treaty of alliance with Germany. General mobilization was ordered the next day and, in the following weeks, concessions granted to foreign powers under the capitulations were cancelled. It remained for Germany, however, to provide the casus belli. (A Latin expression meaning the justification for acts of war). Two German military vessels, the battleship Göben and the heavy cruiser Breslau, had been caught in a neutral Ottoman port when war broke out in Europe and were turned over to the Ottoman navy. In October they put to sea with German officers and crews and shelled Odessa and other Russian ports while flying the Ottoman flag.
Russia declared war on the Ottoman Empire on November 5, 1914.
Caucasus Campaign Map 1914 - 1916
Enver launched an ill-prepared offensive in the winter of 1914-15 against the Russians in the Caucasus, vainly hoping that an impressive demonstration of Ottoman strength there would incite an insurrection among the tsar's Turkish-speaking subjects. Instead, a Russian counteroffensive inflicted staggering losses on Ottoman forces, driving them back to Lake Van.
Russia left the war after the Bolshevik Revolution in 1917. The new Russian government concluded the Treaty of Brest-Litovsk with the Central Powers in March 1918, under which the Ottoman Empire regained its eastern provinces.
Entente Powers of France, Great Britain and Russia
The Entente Powers comprised a military alliance - driven by a variety of inter-related treaties - of France, Great Britain and Russia. While the Entente Alliance was by no means a formal alliance, inter-twining treaties effectively rendered it thus. The term itself was much used in 1914 and 1915, but was replaced by the more general 'Allies' thereafter, and was taken to include other nations including Italy and Japan.
Central Powers of Austria-Hungary and Germany
In opposition to the Entente alliance were the Central Powers, another alliance of great powers: Austria-Hungary and Germany. This ensured that pre-war Europe was essentially dominated by two armed camps. Germany had a long-standing alliance with the fading Austro-Hungarian Empire dating back to the 1870s. Other treaties (for example both sides allied to Italy at various stages) combined to ensure a tangled alliance system in 1914; by the close of the war the Central Powers had been extended to incorporate Bulgaria and Turkey.