The “walled oases” phenomenon. A study of the ramparts in Dūmat al-Jandal and other pre-Islamic sites in north-western Arabia

The present article focuses on a long-lasting phenomenon that has not yet been treated from a regional and comparative perspective, despite its exceptional character: the walled oases of north-western Arabia. It appears that several oases in the region (Al-Ḥuwayyiṭ, Dūmat al-Jandal, Ḥāʾiṭ, Khaybar, Qurayyah and Taymāʾ) were entirely, or in large part, enclosed by outer walls prior to the Islamic era. These compounds comprised not only densely populated areas but the whole oasis territory, including rural zones and sometimes burial grounds. Measuring several kilometres in length, these immense defensive schemes required considerable investment by indigenous populations for their construction and maintenance until their disuse. According to our research, the walled oases phenomenon in north-western Arabia originated sometime in the late fourth−early third millennium BCE, possibly inspired by Early Bronze Age southern Levant defensive concepts, and further expanded in connection with the emergence of the trans-Arabian trade and the caravan kingdoms. These conclusions are based on the detailed technological study of the ramparts of the oasis of Dūmat al-Jandal and on the analysis of satellite imagery and scientific literature on other sites in north-western Arabia.