Monograph on the Aden Hinterland is an intelligence report prepared in 1908 by a British army major, Harold Jacob (1866–1936), who was posted to the mountainous areas north of the port town of Aden. It is a richly detailed account of tribal life and practical politics. Jacob led the commission to demarcate the border between the Aden Protectorate and Ottoman Yemen. The detachment operated over difficult terrain, encountering sometimes violent opposition from the inhabitants. The report is marked “secret” and was printed for use by the Aden administration and for the information of the government of India in Bombay. It covers the complex and confusing political situation in the Dhala tribal areas and the need to combine knowledge of the people with military firmness and administrative finesse, qualities that Jacob found lacking in the distant governments of Aden and Bombay. In his view, the British could not advise rulers, in this case the amir of al-Dhala (present-day Ad Dhale’e), “without a perfect and detailed grasp of the habits of the people, their language and customs, and this most essential knowledge cannot be obtained without our living, moving and having our being with the people.” During his long career in Aden, Jacob was in turn political agent in upland Aden, first assistant resident in the Aden settlement, and political advisor in the settlement to the British Army during World War I. After the war he became advisor on Arabian affairs to the British High Commissioner in Cairo. Jacob is the author of Perfumes of Araby:Silhouettes of Al Yemen (1915), Kings of Arabia: The Rise and Set of the Turkish Sovranty in the Arabian Peninsula (1923), and The Kingdom of Yemen: Its Place in the Comity of Nations (1933).