The Nile is a river and therefore has no 'capital'.
Cairo - the Nile runs through it.
Yes, the Nile flows through Cairo which is the capital of Egypt.
Cairo, the capital and largest city of Egypt, borders the Nile River.
Khartoum, Sudan
The Nubian capital was in North East Africa near the Nile River.
Nubia is a region, not a country, in Southern Egypt along the Nile. There is no capital.
The Blue Nile and White Nile meet in Sudan, near Khartoum, the Sudanese capital.
The Blue Nile and the White Nile converge at Khartoum, Sudan.
The White Nile and Blue Nile merge to form the river Nile near Khartoum, Sudan, at a place known as "al-Mogran".
Khartoum near where it meets the White Nile
Cairo
The best known are - Cairo the capital of Egypt and Khartoum the capital of Sudan.