On the great Roman sites, there is a succeeding Christian Period which simply involves a switch from pagan worship to early Christian ritual.

The day-to-day language was Coptic, the latest form of the ancient Egyptian language, although Greek was used for administration and commerce. The oasis population apparently decreased, perhaps because many oasis settlers returned to their Nile Valley origins when the Roman trade empire broke up.

Ismant el-Kharab: the large East Church before excavation. Subsequent work has dated the church to mid-Fourth Century

Textual references allude to a well organized religious community, including a bishop, deacons, and monks and we know of five churches. There are almost certainly, several more. In this period there were also Manichaeans at Ismant el-Kharab, living side by side with pagans and Christians and together making a very interesting grouping.

Culturally and physically the three are so far indistinguishable, making it difficult to identify their presence in an archaeological context.