> and began to depend on Sicily and Egypt to produce the grain for Rome Later in the fourth century there were lots of shenanigans around securing the grain su

> and began to depend on Sicily and Egypt to produce the grain for Rome Later in the fourth century there were lots of shenanigans around securing the grain supply for the capital which in that period had shifted to north africa. I don't think we can rule out soil degradation as the reason for the shifts in the productive regions across ancient history, like how Paestum turned into a swamp due to soil erosion.