WW1, the Ottoman Empire declares war, 1914 CE
Today on the 14th of November in 1914 CE, the Ottoman religious leader or Sheikh-ul-Islam declared an Islamic holy war on behalf of the Ottoman government, urging the Muslims to take up arms against Britain, France, Russia, Serbia, and Montenegro in World War I. The decree or Fatwa was publicly read out in front of a large crowd in Istanbul.
In the First Balkan War (1912-1913), the Ottomans lost almost all of their territory in Europe. In WWI, the Ottomans allied themselves with one of the great European powers to help safeguard them against future loss. Therefore, Sultan Mehmed V joined the Germans to fight against the Allied Powers.
The Ottomans lost and the Armistice of Mudros (signed on 30 October 1918) marked the end of Ottoman participation in WW1. The war fundamentally changed the shape of the Ottoman Empire. Victorious states partitioned the empire, thus causing its end.
During the war, separatist nationalist movements, such as those of the Arabs and Armenians, intensified their activities. The Arab Revolt began in June 1916 that demanded to create of an independent Arab state. With their defeat in WW1, the Ottoman territories including the capital city of Istanbul were occupied by the Allied powers.
In reaction to the foreign occupation of Ottoman lands and the burgeoning separatist movements, a Turkish national resistance movement emerged in 1919–1922 that drove the occupation forces back, toppled the sultanate, and created the modern Turkish Republic.