The ancient Egyptian kingdoms, at their greatest extent, stretched more than 2000 kilometres along the Nile and passed through diverse habitats. In the north, the Nile traversed the Mediterranean coast and the Delta, while further south a thread of cultivation along the Nile Valley passed through the vast desert of the Sahara. As global climate and landscapes changed and evolved, the habitable parts of the kingdoms shifted. Modern studies suggest that episodes of desertification and greening swept across Egypt over periods of 1000 years. Rather than isolated events, the changes in Egypt are presented in context, often as responses to global occurrences, characterised by a constant shift of events, so although broadly historic, this narrative follows a series of habitats as they change and evolve through time.
The Nile is one example of a large river interacting with a civilisation. A number of other rivers in China, in Mesopotamia and elsewhere share similarities with the Nile. Students of these other rivers may be interested in this Element.