The Nile (also known as the Nile River or River Nile) is an important river in Africa that flows northwards into the Mediterranean Sea. At roughly 6,650 km (4,130 mi) long, it is among the longest rivers in the world. Its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Eritrea, South Sudan, Sudan, and Egypt. It plays an important economic role in the economy of these nations, and it is the primary water source for South Sudan, Sudan and Egypt.
The Nile has two major tributaries: the White Nile and the Blue Nile. The White Nile, being the longer, is traditionally considered to be the headwaters, while the Blue Nile actually contributes 80% of the water and silt below the confluence of the two. The White Nile begins at Lake Victoria and flows through Uganda and South Sudan, while the Blue Nile begins at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet at the Sudanese capital of Khartoum.
After Khartoum the river flows north, almost entirely through the Nubian Desert, to Cairo and its large delta, joining the Mediterranean Sea at Alexandria. Egyptian civilization and Sudanese kingdoms have depended on the river and its annual flooding since ancient times.