The celebrations of 1908 did not last. Within months the empire began losing territory again. Austria-Hungary annexed Bosnia in 1908, Bulgaria declared full independence, and Italy seized Libya in 1911 and 1912. Then Serbia, Greece, Bulgaria and Montenegro attacked together. In the Balkan Wars of 1912 and 1913 the empire lost almost all its remaining land in Europe. Hundreds of thousands of Muslim refugees fled into Anatolia, carrying stories of massacre and expulsion. In 1913 a coup brought the Committee of Union and Progress fully to power, dominated by three men: Enver, Talat and Cemal Pashas. Their politics hardened toward a Turkish and Muslim nationalism, shaped by fear that the empire's remaining Christians would be the next to break away with foreign help.
Into the world war
In late 1914 the empire entered the First World War. Early campaigns went badly; in the winter of 1914 to 1915 Enver led an army into the Caucasus mountains against Russia, and most of it was lost to cold and defeat at Sarıkamış. Ottoman leaders blamed Armenians, some of whom lived on both sides of the Russian border and some of whom fought for Russia, and they treated a whole people as an enemy within.
The Armenian genocide
On April 24, 1915, Ottoman authorities arrested hundreds of Armenian community leaders and intellectuals in Constantinople; most were later killed. Armenians mark the date each year in remembrance. In the following months the government ordered the deportation of Armenians from across Anatolia. Men were often separated and shot. Women, children and the elderly were marched through mountains and deserts toward Syria, robbed, assaulted and killed along the way by soldiers, irregular units and local bands, with tens of thousands dying of hunger, thirst and disease in camps around Deir ez-Zor. Many women and children were forcibly converted and absorbed into Muslim households. Most scholars estimate that between about 600,000 and 1.5 million Armenians died, with many putting the figure at around a million or more. Assyrian and Greek Orthodox Christians also suffered mass killing and deportation. Some Ottoman officials, such as Mehmed Celal Bey, governor of Aleppo and later Konya, tried to resist the orders, and some Muslim neighbors hid Armenians at great risk.
The events were documented at the time. Ottoman courts-martial in 1919 and 1920 convicted top wartime leaders, including Talat, Enver and Cemal, in their absence, though few sentences were carried out. Raphael Lemkin, who coined the word "genocide" in 1944, cited the fate of the Armenians as one of the cases that shaped his thinking. Most historians and genocide scholars call the events a genocide. The Turkish state acknowledges that many Armenians died in wartime relocations and conflict but rejects that term, and the question remains politically charged. Learning it carefully honors the victims and protects the principle that no people may be treated as disposable.
From empire to republic
In 1916 an Arab Revolt led by Sharif Hussein of Mecca rose against Ottoman rule, and British forces advanced into Iraq and Palestine. The empire signed an armistice at Mudros in October 1918, and Allied troops occupied Istanbul. The Treaty of Sèvres in 1920 would have carved up Anatolia among the Allies, Greece, an Armenian state and a possible Kurdish region. A national movement led by the general Mustafa Kemal, later called Atatürk, refused it and fought Greek, Armenian and French forces. After defeating the Greek army in 1922, the nationalists negotiated a new settlement. The Treaty of Lausanne in 1923 replaced Sèvres and recognized the borders of a new Turkish state.
The dynasty's end came in stages. The Grand National Assembly abolished the sultanate in 1922 and the caliphate in 1924, and the Republic of Turkey was proclaimed in October 1923 with Ankara as its capital. The last sultan, Mehmed VI, left on a British warship.
The settlement also included a population exchange. The 1923 Greek and Turkish population exchange sorted people by religion, not language: about 1.2 million Orthodox Christians were sent to Greece, including some who spoke only Turkish, and about 400,000 Muslims went to Turkey, including some who spoke only Greek.
Worked example: weighing the evidence
How do historians establish what happened in 1915, given denial? They look for converging sources that had no reason to agree. Germany was the Ottoman ally, yet German consuls and officers sent detailed reports of deportations and massacres to Berlin. American missionaries and diplomats wrote similar accounts. The United States ambassador, Henry Morgenthau, wrote in his memoir of 1918 that when the Turkish authorities ordered the deportations, "they were merely giving the death warrant to a whole race," and that they made little effort to hide this in conversations with him. Survivors gave thousands of testimonies. Ottoman court records from 1919 include orders and testimony from officials. And the demographic record shows that an ancient Armenian presence across eastern Anatolia nearly vanished.
Each source has limits. Ambassadors had political aims, survivors remembered through trauma, and postwar trials took place under Allied occupation. But when enemies, allies, neutrals, victims and the state's own investigators describe the same pattern, the conclusion becomes very hard to avoid. The same method works for any contested atrocity: ask who reported it, what they had to gain, and whether independent witnesses agree.