The Nile River, Giza

The Nile River is the longest river in the world, although some Brazilian scientists are currently claiming that the Amazon River is longer. It is 4,132mi (6,650km) long and travels through or on the border of ten African countries. It begins in the rivers that flow into Lake Victoria, north of Tanzania and flows northwards, draining into the Mediterranean Sea. It has two tributaries: the White Nile from Central Africa, considered as the primary stream and the Blue Nile from Ethiopia, considered as the main source of water up to 80% and silt.

The two meet in Khartoum, Sudan, and become the Nile. The river is the main water source for both Egypt and Sudan. The Nile was the lifeline of the Ancient Egyptians. The river flooded each year between June and September. This was due to the heavy summer rains and melted snow that was sent down the Ethiopian mountains into the Nile and overflowed the riverbanks. The Egyptians used to call this "akhet", the inundation. The flood brought with it dark, fertile soil that was necessary for cultivating the farmlands with wheat, flax and papyrus. The dark soil deposit was called "kemet", the black land, and it was about 13mi (20km) wide. Either side of this was the "deshret", the red land which was the desert area. The deshret provided protection from foreign conquerors, and in the north, where the land was swampy, made it impossible for outsiders to cross.

Besides fertile soil, the Nile was also a source of water, transportation and travel. Boats and rafts were built to transport building materials such as stone for large scale projects like the pyramids. It is thought that funerary boats could have been used to carry deceased Pharaohs down the Nile to the afterlife or possibly used to carry them across the Nile to be mummified and buried.

The calendar of the Egyptians was created around the Nile's yearly cycle. It had three seasons: inundation, growing season and harvest season. Great famine has occurred during times of drought, but none worse than during Djoser's reign (Pharaoh of the stepped pyramid) when the Nile failed to flood the plains for seven years. The Famine Stela is an inscription carved into stone that tells the story of Djoser sending his vizier Imhotep to seek answers. Imhotep was visited in his dreams by the god of fertility, Khnum, who promised to make the Nile flow again. Imhotep recounted his dream to Djoser, who, in turn, issued a decree to have Khnum's temple restored and regular offerings made to the god. Soon after, the Nile began to flow once again.

The annual flooding was one of the most important events during Ancient Egypt, except for high-water years when whole crops were destroyed or drought years that caused famine. Today, the flow of the Nile is controlled via a dam in Aswan, where the reservoir can store the water for release during drier years. This protects the local farmers and the trademarked Egyptian Cotton crop that is grown on the Nile Delta. As Egyptologist Zahi Hawass once said, "The Nile is the soul of Egypt".