Nili in the context of The National Archives (United Kingdom)

The Middle Eastern theatre of World War I saw action between 30 October 1914 and 30 October 1918. The combatants were, on one side, the Ottoman Empire (including the majority of Kurdish tribes and Circassians, and the relative majority of Arabs), with some assistance from the other Central Powers; and on the other side, the British (with the help of a small number of Jews, Greeks, Armenians, some Kurdish tribes and Arab states, along with Hindu, Sikh and Muslim colonial troops from India) as well as troops from the British Dominions of Australia, Canada, and New Zealand, the Russians (with the help of Armenians, Assyrians, and occasionally some Kurdish tribes), and the French (with its North African and West African Muslim, Christian and other colonial troops) from among the Allied Powers. There were four main campaigns: the Sinai and Palestine, Mesopotamian, Caucasus, and Gallipoli campaigns. There were four more minor campaigns in Persia, South Arabia, the Arabian interior, and Libya.

Both sides used local asymmetrical forces in the region. On the Allied side were Arabs who participated in the Arab Revolt and the Armenian militia who participated in the Armenian resistance supported by Russia during the War; along with Armenian volunteer units, the Armenian militia formed the Armenian Corps of the First Republic of Armenia in 1918. In addition, the Assyrians joined the Allies and saw action in Southeastern Turkey, northern Mesopotamia (Iraq), northwestern Iran and northeastern Syria following the Assyrian genocide, instigating the Assyrian war of independence. Turks were persecuted by the invading Russian troops in the east and by Greek troops and Armenian fedayis in the west, east, and south of Anatolia. The theatre covered the largest territory of all theatres in the war.