The Ottoman Empire, with its capital at Constantinople since 1453, had been founded in 1299. It attained its greatest extent in 1683. By the time of the First World War, it had been in decline for a while and was known as the "sick man of Europe." In the Balkan Wars of 1912 and 1913, it lost all of its remaining territory in Europe except for East Thrace, although it still controlled a significant amount of territory in Anatolia and the Middle East. In November 1914, the Ottoman Empire entered the First World War on the side of Germany and Austria-Hungary. Russia attacked the Ottoman Empire on its Caucasus frontier, and made significant progress aided by Armenians within the Ottoman Empire. In response, the Ottoman Empire massacred significant numbers of its Armenian subjects. The Ottoman Empire was initially successful against Britain and France at Gallipoli and Kut, but were unable to cope with an Arab revolt, assisted by British money and officers (the best-known of whom was Captain T. E. Lawrence), and the British steadily began to sieze territory in Palestine and Syria. The Armistice of Mudros, signed on October 30, 1918, ended the war in this region. Under the terms of the Treaty of Sèvres, the Empire was to be dismantled; however, the treaty was never implemented; during the Turkish War of Independence, Turkish revolutionaries overthrew the Sultan, eventually instituting a republic, and annulled the Treaty of Sèvres. Under the 1923 Treaty of Lausanne, Turkey retained sovereignty over Anatolia as well as East Thrace.
