Why was the nile called the lifeblood of ancient egypt?

As the nile river would over flow, the water would look like blood. Also, there was a battle in the river and many people have died.

The Nile River has been called the lifeblood of Egypt because it is in many ways the source of life in Egypt and has been for centuries. The Nile River has provided vital natural resources to the Egyptian people in the form of water, plants and animals, fertile soil, a route of transport, and also power. The Nile River continues to be a vital resource providing Egypt with power through the Aswan High Dam and many other vital resources such as the fertile soil in the Nile River Delta.

The feudalism i believe