ABSTRACT
I N no country has geography determined history more than in Arabia. Except for the south~west, most of it is so unproductive that foreign invasion has been very rare. As in Persia, the position of the deserts has hindered the unification of those regions in which the strongest states have arisen, the Yemen, the Hejaz, the oases of central Nejd and 'Oman. The aridity of many districts has forced nomadic life and tribal organization on their inhabitants. Warfare has been almost incessant throughout their history; their political allegiance has usually meant little and changed readily· without affecting their way of life and the nature of their society. Similar geographical conditions extend north of the peninsula in the Syrian desert, and the Arabs, skilled in desert travel, have been able to move freely across it to plunder, trade, or settle in the valleys of the Euphrates and the Jordan.
