<P> The civilization of Ancient Egypt was indebted to the Nile River and its dependable seasonal flooding . The river's predictability and the fertile soil allowed the Egyptians to build an empire on the basis of great agricultural wealth . Egyptians are credited as being one of the first groups of people to practice agriculture on a large scale . This was possible because of the ingenuity of the Egyptians as they developed basin irrigation . Their farming practices allowed them to grow staple food crops, especially grains such as wheat and barley, and industrial crops, such as flax and papyrus . </P> <P> The civilization of ancient Egypt developed in the arid climate of northern Africa . This region is distinguished by the Arabian and Libyan deserts, and the River Nile . The Nile is one of the longest rivers in the world, flowing northward from Lake Victoria and eventually emptying into the Mediterranean Sea . The Nile has two main tributaries: the Blue Nile which originates in Ethiopia, and the White Nile that flows from Rwanda . While the White Nile is considered to be longer and easier to traverse, the Blue Nile actually carries about two thirds of the water volume of the river . The names of the tributaries derive from the color of the water that they carry . The tributaries come together in Khartoum and branches again when it reaches Egypt, forming the Nile delta . </P>

What important event took place each year that provided rich soil around the nile river