The Nile river is the longest river in the world at 6,650 kilometers (4,135 miles). The Nile is Longer than the distance from New York City to London.
But the length of this river was not constant, it changed as the course changed.
Below is a map which shows how the Nile River has changed its course over the past 5,000 years (in relation to Old and Middle Kingdom pyramid sites).
500 years before the present day (BP)
1000 years BP
1500 years BP
2000 years BP
2500 years BP
3000 years BP
3500 years BP
4000 years BP
4500 years BP
5000 years BP
Dots indicate settlements and Pyramids.