Ecologically marginal regions do not tend to stand in the focus of either the institutions of ancient societies or modern research. The paper explores how the region from the western fringes o Nile Delta to the Gulf of Sollum with no economic potential at first sight and little political significance in Roman to Byzantine times was used, exploited and what infrastructure it had. By comparing three areas or sites - the religious center of Abu Mena, the steppe zone south of Marsa Matruh and a fortlet close to Sollum, that cover a time range from 1st c. to the 7th/8th c. CE - I inquiry into the various reasons for investing or living in this region and when and why it stopped (which is the more difficult part). Even though there is no doubt of its ecological marginality, regional interdependencies and historical trajectories come to the fore that might shed a different light on developments in the "core areas" such as the Cyrenaica or the Nile Valley. Since marginal regions can be either more resilient when it comes to changes or more fragile, they can help understanding changes in the more "central" regions.