By 1800 the Ottoman government was utterly corrupt, and the empire was no longer a first-rate power. Selim III (ruled 1789–1807) planned widespread reforms, but he was deposed and killed at the instigation of the Janissaries and the ulema.

The major European powers began to take an interest in what they called the Eastern Question—the fate of the Ottoman Empire. They recognized that a collapse of the Ottoman Empire would lead to bitter conflicts over its territories At the Congress of Vienna, 1814–15, Britain, Austria, Prussia, and Russia agreed that Turkey must be p reserved.

Sultan Mahmud II (1808–39) had the entire Janissary corps slaughtered in 1826. He then initiated an era of reform, aided by Prussia. Meanwhile, the Balkans were breaking out in rebellion to gain independence. Serbia, Greece, Romania, and Bulgaria all shook off Turkish rule by 1880.

France began a conquest of Algeria in 1830. In 1831 Mohammed Ali, governor of Egypt, seized control of Palestine and Syria and sent an army into Anatolia. He was forced by the European powers to withdraw in 1840.

Meanwhile, Russia continued its advance into Ottoman lands. There were four Russo-Turkish wars during the century—including the Crimean War, in which Britain and others aided Turkey. Despite its support of Turkey during the Crimean War, Britain occupied Egypt in 1882.

Abdul Hamid II adopted a constitution in 1876. Two years later he suspended it and assumed absolute powers, backed by secret police. In 1889 students formed a secret society opposed to the sultan's despotic rule This action was the origin of the Young Turks movement, which was soon joined by many young army officers Under the leadership of Enver Pasha and Mustafa Kemal (later known as Kemal Atatürk), the movement became so strong that in 1908 Abdul Hamid reinstated the constitution. In 1909 he was replaced by a figurehead sultan.

Libya was annexed by Italy after a war in 1911–12. As a result of the Balkan Wars, 1912–13, the Ottoman Empire lost its remaining territory in Europe, except for a small area around Constantinople. In 1914 Turkey entered World War I in support of Germany. The Allied victory cost Turkey much of its territory. Mustafa Kemal formed a provisional goverment in 1920; in 1922 the sultanate was abolished.

Meanwhile, in the 1890's, thousands of Armenians within the empire were slaughtered by the Turks because of their agitation for independence During World War I, the Turks. fearing treachery from the Armenians, made an effort to rid the empire of them through murder and deportation. By the end of the war, some 1.2 million Armenians had been killed.