The word "Nile" comes from Greek word Neilos. In the ancient Egyptian language, the Nile is called Iteru,meaning "great river".There are two great tributaries of the Nile, joining at Khartoum: White Nile and Blue Nile. The other tributary is Atbara.White Nile originates from the lake Tana of Ethiopia, in East Africa and is about 500 miles long.It flows only when there is rain in Ethiopiaand dries very fast. It joins the whiye Nile approximately 200 miles north of Khartoum. Its last tributary Atbara joins roughly halfway to the sea. From that point north, the nile diminishes because of evaporation.The course of the Nile in Sudan is distinctive. It flows over six groups of cataracts, from the first at Aswan to the sixth at Sabaloka (just north of Khartoum)and then turns to flow southward for a good portion of its course , before again returning to flow to the north to the sea making an horse-shoe. this is called the "great bend of the Nile."North of Cairo , the Nile splits into two branches that feed the mediterranean : the Rosertta Branch to the west and the Damietta to the east, forming the Nile Delta.
Two questions were heard since ancient times. 1. Where does the Nile begin ?, 2. What causes the yearly floods that make the river banks so fertile? 
