Answer:
When Herodotus, the ancient Greek historian, wrote these words, Egyptian civilization had been going successfully for thousands of years without foreign interference. These unusual people, thanks to the uniquely protective Nile River Valley, had the opportunity to develop differently from Europe and the East. Long periods of isolated growth without foreign invasion occurred because Egypt had natural borders that were impossible, or very difficult to cross.
So immense is the significance of the Nile River to the development of Egyptian civilization, that we cannot separate the history of Egypt from its geography and other natural aspects. The Nile was very important as a communication and trade route across a vast and harsh land. Also, its annual flooding renewed farmlands that would otherwise be arid desert.
