A term invented by George Reisner and used by Egyptologists to designate the inhabitants of Nubia in the Predynastic Period, Early Dynastic Period, and the early Old Kingdom. The people appear to have been herders and farmers. They are known from cemetery sites and a few Egyptian texts that describe Egyptian military activities against them. Such action may have contributed to their eventual disappearance. An alleged B-Group who succeeded them is now regarded as fictitious.
See also C-Group.
Historical Dictionary Of Ancient Egypt by Morris L. Bierbrier
Ancient Egypt. A Reference Guide. EdwART. 2011.