On June 5th, 1916, Arab irregulars attacked the city of Medina under the orders of Hussein bin Ali, the Sharif of Mecca. This offensive operation was the first in a series of events that would stretch out of World War I, the Arab Revolt. In the months prior he had contacted representatives from the British Empire, who had promised aid in the form of gold, weapons and ammunition if the Arabs joined them against the Ottoman Empire. Many prominent leaders in Istambul were supporters of a radical Turkish-nationalist wing in the Ottoman government, and the state was undergoing a process of "turkification" which greatly angered its minorities, including the Arabs. Though that action was unsuccessful, five days later another group of irregulars attacked Mecca, putting the city under siege. With the aid of British regular troops from Egypt, Mecca was seized on July. Ottoman artillery fire had greatly damaged the holy city, an act which Hussein capitalised on to rally Arabia's devout population. British high command sent a number of officers to assist the Arabs with contemporary military tactics and strategy, as well as to act as liasons and information-gatherers. The most famous and influential of these was Captain Thomas Edward Lawrence, whose friendship with the revolt's leaders and knowledge on irregular warfare helped shape the Middle East's borders.
Medina and its railway were abandoned early in the revolt, as it became clear that British troops rampaging through Palestine would soon cut them off. The real breakthrough occurred when British forces seized Baghdad in February of 1917. As they kept pushing north, and it became clear that the Entente would likely lose this war, British high command authorised one last plan of revenge. On September 27th, 1917, and with full recognition from all remaining Entente nations, Sharif Hussein bin Ali proclaimed the Hejaz Caliphate, challenging the Ottoman claim to that title on the basis of descending from the Hashemite family (direct descendands of Muhammad) and controlling the three holiest cities in Islam. By this time, the Istambul government was collapsing from Armenian, Greek, Assyrian and Kurdish insurrections, despite genocidal campaigns against these groups. Largely with American weapons and British officers, the Regular Arab Army was established, mostly under the command of Hussein's son Faisal, who had T. E. Lawrence as his right hand.
In November of 1918, with only Britanny and the surrounding regions holding out against German attacks, and the Royal Navy decimated, an armistice was signed. Entente troops in the Middle-East, however, did not surrender their arms as the terms dictated, they simply handed them over to their insurrectionist allies and then gave themselves up. Thousands of French, Oceanykan, American and British volunteers chose to remain with the Regular Arab Army or similar movements, adopting local-sounding names (including most infamously T. E. Lawrence). They held a line from Adana, though Kayseri, to Trabzon and were recruiting every able-bodied male for an attack on Ankara.
This attack began on March of 1919, with over 240,000 deserters, conscripts, guerillas, irregulars and tribal fighters racing for the Ottoman Empire's second largest city. Istambul's government tasked Mustafa Kemal Ataturk with stopping them, granting him command of the best-equipped and most capable troops in the Ottoman Army, a mission which he succesfully accomplished at the Battle of the Salty Lakes. Discontent in the Turkish population had reached a boiling point, and protests erupted demanding peace with the other nationalities of the Empire, which were sure to begin performing crimes against humanity against the Turks for actions such as the Armenian, Assyrian, Kurdish and Greek genocides which Ottoman troops had carried out during World War I. When the Turkish Revolution broke out, Ataturk's Ankara-based forces immediately sought a ceasefire with the insurrectionists to protect his rear, promising independence and a stop to all massacres, deportations and death marches. The rebels agreed, thus peace was finally achieved on May 8th.