The study of the archaeological material, and particularly the pottery, from the latest occupation levels at Mleiha and ed-Dur allowed us to date the end of their occupation to the second half of the 3rd century AD, and most likely to the middle of that century. These sites were the main centres of a culture that had settled and developed in South-East Arabia from the 3rd century BC. Both sites were abandoned as the Sasanian power grew in the Arabian Gulf, which brought about a change of the settlement pattern in that region up to the beginning of the Islamic period and even later.