It has been established in the preceding sections that settlement walls were by no means uncommon in ancient Egypt, and it is from this tradition that the late Roman and early Islamic urban configuration developed. With the incorporation of the country into the Roman empire, it was inevitable that changes would be made to its defensive situation, and the continuing Hellenization of the upper classes would alter perceptions of the urban ideal. This section will consider to what extent these forces brought Egypt into line with other eastern Roman provinces, and how the urban enceinte developed after the Arab conquest of the country in 642.