Question: What is the prenomen or royal name of the ancient ruler of Egypt and a kingdom at the confluences of the Blue Nile, White Nile, and River Atbara?

Context paragraphs:
Sobat River: The Sobat River is a river of the Greater Upper Nile region in northeastern South Sudan, Africa.  It is the most southerly of the great eastern tributaries of the White Nile, before the confluence with the Blue Nile.

Gezira Scheme: The Gezira Scheme (Arabic: مشروع الجزيرة‎ ‎ ) is one of the largest irrigation projects in the world.  It is centered on the Sudanese state of Al Jazirah, just southeast of the confluence of the Blue and White Nile rivers at the city of Khartoum.  The Gezira Scheme was begun by the British while the area was governed as part of Anglo-Egyptian Sudan.  Water from the Blue Nile is distributed through canals and ditches to tenant farms lying between the Blue and White Nile rivers.

Burkhart Waldecker: Burkhart Waldecker was a German explorer who, in 1937, discovered the most southern source of the White Nile in Burundi.  Waldecker came to the area to seek asylum from Nazi persecution.  The true source is near Rutovu, where a pyramid was erected in 1938.  Waldecker's name is seen on the plaque, which says in Latin, "Caput Nili," thus ending man's long quest to discover the source.  The Nile river has various sources, Waldecker found the White Nile's most southern source which is part of the Kagera River, the other being Lake Kyoga in Uganda further north.  The small pipe flowing with the first Nile water appears from the ground below the summit of Mount Kikizi where the pyramid is found.

Blue Nile: The Blue Nile is a river originating at Lake Tana in Ethiopia.  With the White Nile, the river becomes one of the two major tributaries of the Nile.

Khartoum: Khartoum ( ) is the capital and largest city of Sudan and the state of Khartoum.  It is located at the confluence of the White Nile, flowing north from Lake Victoria, and the Blue Nile, flowing west from Ethiopia.  The location where the two Niles meet is known as ""al-Mogran"" (المقرن " the confluence ").  The main Nile continues to flow north towards Egypt and the Mediterranean Sea.

Synodontis khartoumensis: Synodontis khartoumensis is a species of upside-down catfish that is native to the Democratic Republic of the Congo, Sudan and Uganda where it occurs in Lake Albert and the Nile basin.  It was first described by Yousif Babiker Abu Gideiri in 1967.  The original specimens were obtained in the Blue Nile, about 2 miles away from the confluence of the Blue Nile and the White Nile, near Khartoum, Sudan.  The species name "khartoumensis" is derived from the city of Khartoum, where the type species was originally found.

Kingdom of Kush: The Kingdom of Kush or Kush ( ) was an ancient kingdom in Nubia, located at the confluences of the Blue Nile, White Nile and River Atbara in what is now Sudan and South Sudan.

Tantamani: Tantamani (Assyrian "UR-daname"), Tanutamun or Tanwetamani (Egyptian) or "Tementhes" (Greek) (d. 653 BC) was a Pharaoh of Egypt and the Kingdom of Kush located in Northern Sudan and a member of the Nubian or Twenty-fifth dynasty of Egypt.  His prenomen or royal name was Bakare which means "Glorious is the Soul of Re."

Sennar (state): Sennar (Arabic: سنار‎ ‎ "Sannār ") is one of the 18 wilayat or states of Sudan.  It has an area of 37,844 km² and a population of approximately 1,100,000 (2000).  Sinar State is delimited by Al-Gazira State in the north, The Blue Nile State in the south, Al-Gedaref State and the Sudanese Ethiopian borders in the east and the White Nile State & the Upper Nile State of South Sudan in the west.  Singa is the capital of Sennar State.  Another significant town is Sennar (or Mukwar), the largest city in the state and other rich commercial towns including El-Suki locality, and El-Dinder locality.  The main economic activity is agriculture with the irrigated scheme of Suki, the sugar factory of Sennar and a number of fruit growers (including bananas and mangoes) located on the banks of the Blue Nile.  In terms of education The University Of Sennar is the only higher education university throughout all the state attended by all its residents.

List of rivers of Egypt: There is only one year-round river in Egypt, the Nile.  It has no non-seasonal tributaries for its entire length in Egypt, though it has two further upstream, the Blue Nile and White Nile, which merge in central Sudan.

Supporting paragraphs: Tantamani Kingdom of Kush
Answer: Bakare