Geography has been defined as the study of space relationships, and it is in this sense that the geography of Palestine must be considered, for upon these relationships very much of its history depends. They are threefold in nature and involve the relation of each region within the country with the other internal regions, of Palestine with the Levant coast of which it is a part, and finally the relation of the Levant with the larger outside world. This world was enormous indeed, for it was in York in England that Constantine was first proclaimed emperor, an event which was to alter the face of Palestine and bring much grief upon the Jewish people, and it was the rich Asian trade, ranging as far as the East Indies and China, which made the Romans so determined to maintain the Provincia Arabia.

In this context two facts are of fundamental importance: the centrality and the extraordinary smallness of Palestine. The entire Middle East is dominated by three great barriers to settlement and easy movement: the towering mountain chains of central Europe and Asia, the dry, forbidding deserts, and the penetrating fingers of the seas, which hold the whole area in their grip. This constriction has determined both the main concentrations of population and the course of the major routes, followed for century after century by both merchants and warriors. Although the notable trading cities of Tyre, Damascus, Palmyra and Petra lay just beyond the Palestinian borders, the routes they served crossed its territory; for here at the south-western end of the Fertile Crescent the desert, closing in upon the Mediterranean, brings cultivation to an end, and all the roads from Asia to Egypt came together at Gaza, where also the opulent caravans from southern Arabia, bringing the riches of the East to Rome, finally reached the sea.