Nubia is an ancient region formerly extended from the Nile river valley (near the first cataract in Aswan), southward to Sudan (Khartoum), Westward to the Libyan desert and Eastward to the Red Sea. As I told you before, with the construction of the high dam, 100,000 of them had to leave their lands.
Nubians were the first to form a structure similar to a state in the world, as excavations in the 1960's showed. This form of state disappeared with the rise of the 1st dynasty in Egypt. Since then, relationships between Nubians and Egyptians underwent different phases. When Egypt was powerful, part of Nubia was invaded by the Egyptian troops. And in crisis times, part of the empire was invaded by Nubian mercenaries, who seized many fine middle kingdom monuments. During the periods of peace, relationships were friendlier, and trade enriched both countries.