Chad–Nigeria relations in the late 1970s, clashes occurred around Lake Chad, where both countries hoped to exploit oil reserves. Both also sought to defuse these confrontations, first by establishing joint patrols and a commission to demarcate the boundary across the lake more clearly. Then in the early 1980s, the low level of Lake Chad brought a series of tiny islands into view, leading to further disputes and disrupting long-standing informal trade networks. This relationship was also complicated by Nigeria's own instability in the north, generated by rising Islamic fundamentalism. Thousands of casualties occurred as the result of violent clashes in Nigeria throughout
Chad Basin the Wadai capital of Abéché was occupied by the French. The remainder of the basin was divided by the British in Nigeria who took Kano in 1903, and the Germans in Kameroun. The countries of the basin regained their independence between 1956 and 1962, retaining the colonial administrative boundaries. As of 2011, over 30 million people lived in the Chad Basin. The population is growing rapidly. Ethnic groups include Kanuri, Maba, Buduma, Hausa, Kanembu, Kotoko, Bagger, Haddad, Kuri, Fulani and Manga. The largest cities are Kano and Maiduguri in Nigeria, Maroua in Cameroon, N'Djamena in Chad and Diffa in Niger.