The distribution of settlements in the Sudan is affected mainly by physical, political and socioeconomic factors. The physical ones such as those of rainfall and geology, which have a direct bearing on the availability of water, determine the limits of permanent settlements, but within that social, cultural, historical, technological and economic factors affect their number and distribution. The physical factors are nature-given and, although acted upon and modified by man, definitely affect the pattern of settlement distribution and, therefore, the choice of man. The political and economic factors, however, are manmade and certainly reflect man's political and economic behaviour in dividing his territory into political and economic units. In the Sudan, the influence of the political factor became evident after the reconquest