Note on the Tribes of the Aden Protectorate is an annotated list of the Arab tribes and sub-tribes of the Aden Protectorate. The short monograph was prepared by a Captain Knapp of the Royal Artillery. It is undated, but based on internal evidence it can be surmised that it was compiled sometime before administrative functions were transferred from the government of India to the British Foreign Office in 1917. The Aden Protectorate, like the Trucial States of the Persian Gulf and the tribal areas of India’s Northwest Frontier, was based on British treaty arrangements with local tribes, the first of which was concluded in 1886. The Aden Protectorate system ended in the 1960s. In the early days, Britain’s aim was to prevent other European powers from extending their reach to the southern end of the Arabian Peninsula and thus threaten the route to India. Later, British administrative officers became more intimately concerned with the internal affairs of the shaykhdoms. Note on the Tribes of the Aden Protectorate is in the form of an intelligence report that provides information on 14 major tribes and their constituent clans. Each entry includes the name of the tribe, its geographic distribution, climate and topography, a population estimate, villages, principal characteristics (e.g., farming, nomadism, brigandage, and so forth), and treaty obligations. This is not a work of original research. Much of the information it contains was taken from Hunter and Sealy’s An Account of the Arab Tribes in the Vicinity of Aden, published in 1886, and the tables of overland routes were derived from Indian Army reports from 1870 to 1894. There is no title page. The title is handwritten on the front flyleaf. The book was published in Simla, India, at the Government Central Press