The Sharifian Army (الجيش الشريفي), also known as the Arab Army (الجيش العربي), or the Hejazi Army (الجيش الحجازي) was the military force behind the Arab Revolt which was a part of the Middle Eastern theatre of World War I. Sharif Hussein Ibn Ali of the Kingdom of Hejaz, who was proclaimed "Sultan of the Arabs" in 1916, led the Sharifian Army in a rebellion against the Ottoman Empire with the ultimate goal of uniting the Arab people under an independent government. Aided both financially and militarily by the British, Husayn's forces gradually moved north through the Hejaz and, fought alongside the British-controlled Egyptian Expeditionary Force, eventually capturing Damascus. Once there, members of the Sharifian Army set up a short-lived monarchy known as the Arab Kingdom of Syria led by Faisal, a son of Sharif Husayn.
For centuries in the Hijaz (the western region of Arabia where the Muslim holy cities of Mecca and Medina are located), power was strongly centralized in the hands of the family of the sharif. Members of this family, as descendants of Muhammad, were called Hashemites in English. Unlike many areas of the Ottoman Empire, there were few competing political influences among the urban elite. The tribal chieftains served as intermediaries between their tribes and the sharif but rarely challenged his authority. The sharif's lone political rival was the Ottoman vali (governor) of the region, who was responsible for ensuring Ottoman sovereignty over the region. A power struggle existed between the sharif and the vali; the authority to make decisions switched back and forth between the two over time. Overall, this political climate left a large amount of influence in the hands of the sharif, who in the early years of the 20th century was Sharif Husayn.
Dissatisfied with his limited power, Sharif Husayn began discussions with tribal leaders in the region, Arab nationalists, and the British High Commissioner in Egypt, Sir Henry McMahon.