As I rode along I reflected that nowhere in the world was there such continuity as in the Arabian desert. Here Semitic nomads, resembling my companions, must have herded their flocks before the Pyramids were built or the Flood wiped out all trace of man in the Euphrates valley. Successive civilizations rose and fell around the desert’s edge: the Minaeans, Sabaeans, and Himyarites in southern Arabia; Egypt of the Pharaohs; Sumeria, Babylonia, Assyria; the Hebrews, the Phoenicians; Greeks and Romans; the Persians; the Muslim Empire of the Arabs, and finally the Turks. They lasted a few hundred or a thousand years and vanished; new races were evolved and later disappeared; religions rose and fell; men changed, adapting themselves to a changing world; but in the desert the nomad tribes lived on, the pattern of their lives but little changed over this enormous span of time.