Abstract

European travel reports of the 19th century and excavations in Transjordan created the impression that population numbers were strongly reduced during the Islamic periods, leading to ‘empty’ lands which were only resettled during the early 20th century. This development was considered to be caused by bad (Muslim) governance, nomadic incursions, and environmental degradation. However, our case study near the ancient site Abila of the Decapolis in northern Jordan found that the land was never empty and always fertile, but there is evidence for a rapid and intense landscape change during the Late Byzantine period. This was probably caused by a significant shift to aridity which also triggered socio-economic changes in subsistence strategies from agriculture to nomadism. The climatic change seems to have occurred rapidly within approximately 100 years in the late 6th and early 7th centuries AD and was accompanied by heavy rainfall events. It might have been caused or triggered by the climatic event of the ‘Mystery Veil’ which the Byzantine historian Procopius described in the year 536 AD. During the Medieval period, settlement density increased again until another decline took place in the late Ottoman period. However, the vicinity of Abila was probably never abandoned and the continuity of place names speaks against a larger exchange of population. Rising population numbers and favourable climatic conditions in the early 20th century caused most tribes to settle again, which improved government control.