ABSTRACT
The fourteenth and fifteenth centuries were a period of change in the riverain Sudan, of adjustment to cultural and economic developments impinging from the surrounding countries, and of accommodation to two intrusive groups - the Arabs and the Nilotic-speakers, particularly the Shilluk. The unification of Nubia early in the sixteenth century may be seen as both a Nubian reaction against the invaders, and a positive response to the new economic and social circumstances that the intrusive forces had created.
