The repressive policies of Abdül Hamid II fostered disaffection, especially among those educated in Europe or in Westernized schools. Young officers and students who conspired against the sultan's regime coalesced into small groups, largely outside Istanbul. One young officer, Mustafa Kemal (later known as ÍÍÍÍAtatürk), organized a secret society among fellow officers in Damascus and, later, in Thessaloniki (Salonika) in present-day Greece. Atatürk's group merged with other nationalist reform organizations in 1907 to form the Committee of Union and Progress (CUP). Also known as the Young Turks, this group sought to restore the 1876 constitution and unify the diverse elements of the empire into a homogeneous nation through greater government centralization under a parliamentary regime.

In July 1908, army units in Macedonia revolted and demanded a return to constitutional government. Appearing to yield, Abdül Hamid II approved parliamentary elections in November in which the CUP won all but one of the Turkish seats under a system that allowed proportional representation of all millets . The Young Turk government was weakened by splits between nationalist and liberal reformers, however, and was threatened by traditionalist Muslims and by demands from non-Turkish communities for greater autonomy. Abdül Hamid II was forced to abdicate and was succeeded by his brother, Mehmet V, in 1909. Foreign powers took advantage of the political instability in Istanbul to seize portions of the empire. Austria annexed Bosnia and Herzegovina immediately after the 1908 revolution, and Bulgaria proclaimed its complete independence. Italy declared war in 1911 and seized Libya. Having earlier formed a secret alliance, Greece, Serbia, Montenegro, and Bulgaria invaded Ottoman-held Macedonia and Thrace in October 1912. Ottoman forces were defeated, and the empire lost all of its European holdings except part of eastern Thrace.

The disasters befalling the empire led to internal political change. The liberal government in power since July 1912 was overthrown in January 1913 in a coup engineered by Enver Pasha, and the most authoritarian elements of the Young Turk movement gained full control. A second Balkan war broke out in June 1913, when the Balkan allies began fighting among themselves over the division of the spoils from the first war. Taking advantage of the situation, Ottoman forces turned on Bulgaria, regaining Edirne and establishing the western boundary of the empire at the Maritsa River.

After a brief period of constitutional rule, the leadership of the CUP emerged as a military dictatorship with power concentrated in the hands of a triumvirate consisting of Mehmet Talat Pasha, Ahmet Cemal Pasha, and Enver, who, as minister of war, was its acknowledged leader in the war.

World War I

As the two European alliance systems drew closer to war in 1914, Enver's pronounced pro-German sympathies, shared by many in the military and bureaucracy, prevailed over the pragmatic neutrality proposed by Talat and Cemal. Germany had been pro-Ottoman during the Balkan wars, but 100 the Po Porte had no outstanding differences with either Britain or France in the summer of 1914. In guiding his government toward alignment with Germany, Enver was able to play on fear of the traditional Ottoman enemy, Russia, the ally of Britain and France in the war.

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 canceled. It remained for Germany, however, to provide the casus belli. Two German military vessels--the battleship Göben and the heavy cruiser Breslau --that had been caught in a neutral Ottoman port when war broke out in Europe 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, followed the next day by Britain and France. Within six months, the Ottoman army of about 800,000 men was engaged in a four-front war that became part of the greater conflict of World War I.

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. During the campaign in eastern Anatolia, assistance was given to the Russians by some Armenians, who saw them as liberators rather than invaders. Armenian units were also part of the Russian army. Enver claimed that an Armenian conspiracy existed and that a generalized revolt by the Armenians was imminent. During the winter months of 1915, as the shattered Ottoman army retreated toward Lake Van, a massive deportation of as many as 2 million Armenians was undertaken in the war zone. It shortly degenerated into a massacre, as ethnic Turks and Kurds descended on Armenian villages or slaughtered refugees along the road. The most conservative estimates put the number of dead at 600,000, but other sources cite figures of more than 1 million. The situation of those Armenians who survived the march out of Anatolia was scarcely improved under the military government in Syria. Others managed to escape behind Russian lines. The episode occasioned a revulsion in Western Europe that had its effect in the harsh terms meted out by the Allies in the postwar settlement.

In the spring of 1915, the Allies undertook naval and land operations in the Dardanelles that were intended to knock the Ottoman Empire out of the war with one blow and to open the straits for the passage of supplies to Russia. Amphibious landings were carried out at Gallipoli, but British forces, vigorously opposed by forces commanded by Atatürk, were unable to expand their beachheads. The last units of the expeditionary force were evacuated by February 1916.

In Mesopotamia the Ottoman army defeated a British expeditionary force that had marched on Baghdad from a base established at Basra in 1915. The British mounted a new offensive in 1917, taking Baghdad and driving Ottoman forces out of Mesopotamia. In eastern Anatolia, Russian armies won a series of battles that carried their control west to Erzincan by July 1916, although Atatürk, who was then given command of the eastern front, led a counteroffensive that checked the Russian advance. 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.

Sharif Husayn ibn Ali, the sultan's regent in Mecca and the Hijaz region of western Arabia, launched the Arab Revolt in 1916. The British provided advisers, of whom T.E. Lawrence was to become the best known, as well as supplies. In October 1917, British forces in Egypt opened an offens ive ive into Palestine they took Jerusalem by December. After hard fighting, British and Arab forces entered Damascus in October 1918. Late in the campaign, Atatürk succeeded to command of Turkish forces in Syria and withdrew many units intact into Anatolia.

Ottoman resistance was exhausted. Early in October, the war government resigned, and the Young Turk triumvirate--Enver, Talat, and Cemal--fled to exile in Germany. Mehmet VI (r. 1918-22), who had succeeded to the rule upon his brother's death in July, sued for peace through a government headed by liberal ministers that signed an armistice at Mudros on October 30, 1918, that had been dictated by the Allies. Allied warships steamed through the Dardanelles and anchored off Istanbul on November 12, the day after the end of the war in Europe. In four years of war, the Ottoman Empire had mobilized about 2.8 million men, of whom about 325,000 were killed in battle. In addition, more than 2 million civilians, including both Turks and Armenians, are believed to have died of war-related causes. Talat and Cemal, who were held responsible for the deportation of Armenians and the mistreatment of refugees, were assassinated by Armenian nationalists in 1921. The following year, Enver was killed while fighting the Bolsheviks in Central Asia.

Data as of January 1995