The occupation of the Arab provinces of the Ottoman Empire was achieved by two British armies, the Egyptian Expeditionary Force and the Mesopotamian Expeditonary Force, operating respectively across Sinai from Egypt and up the Tigris and Euphrates from the Persian Gulf. In Mesopotamia civil matters were under the direction of the Government of India and the India Office. The initial difficulties attendant on the taking over of a tract of Turkish territory are a measure of the task of an heir to Ottoman sovereignty. The new machinery of government developed out of the Revenue Department, which, for the reasons above stated, was the first to be established as the most pressing necessity and under which the principal spending departments could conveniently be grouped in the early stages. The complication and variation of systems of land tenure under these circumstances was a formidable embarrassment to the administration.