A. H. Sayce,
The Egypt of the Hebrews and Herodotos
“ On the opposite side of the Nile, a little to the north, was the fortress of Khri-Ahu, which guarded the approach to the river. Where Cairo now stands Herodotos saw only sand and water. Even Khri-Ahu was merely an insignificant village at the foot of a fortress of mud brick; the strong walls and towers of hewn stone in which the Roman legion afterwards kept ward over Egypt were as yet unbuilt. All who could afford it lived in Memphis and its suburbs, and the rock-hewn tombs at the foot of the citadel of modern Cairo are of the Roman age. ”
