Nigerien culture is marked by variation, evidence of the cultural crossroads which French colonialism formed into a unified state from the beginning of the 20th century. What is now Niger was created from four distinct cultural areas in the pre-colonial era: the Zarma dominated Niger River valley in the southwest; the northern periphery of Hausaland, made mostly of those states which had resisted the Sokoto Caliphate, and ranged along the long southern border with Nigeria; the Lake Chad basin and Kaouar in the far east, populated by Kanuri farmers and Toubou pastoralists who had once been part of the Kanem-Bornu Empire; and the Tuareg nomads of the Aïr Mountains and Saharan desert in the vast north.