What is "dotawo"

Dotawo ( Old Nubian: Lower Dau or Daw) was a kingdom that might have existed in the Beja Region of Lower Nubia (Northern Sudan and Southern Egypt) in the Middle Ages. It has long been known that a kingdom by this name is mentioned as existing during the collapse of the Kingdom of Makuria in the thirteenth century. It was reported to be one of the last surviving Christian states in the region.