Lake Chad the Yobe River in Nigeria/Niger. Despite high levels of evaporation, the lake is fresh water. Over half of the lake's area is taken up by its many small islands (including the Bogomerom archipelago), reedbeds and mud banks, and a belt of swampland across the middle divides the northern and southern halves. The shorelines are largely composed of marshes. Because Lake Chad is very shallow—only at its deepest—its area is particularly sensitive to small changes in average depth, and consequently it also shows seasonal fluctuations in size. Lake Chad has no apparent outlet, but its waters percolate into the Soro and
Niger far east as western Niger. The Kanem-Bornu Empire was an empire that existed in modern-day Chad, Nigeria, Cameroon, Niger and Libya. The empire first existed and prospered as the Kanem Empire as early as the 9th century and later as the Kingdom of Bornu until 1900. In the 19th century, contact with Europe began with the first European explorers—notably Monteil (French) and Barth (German)—to travel to Niger. Following the 1885 Berlin conference during which colonial powers outlined the division of Africa into colonial spheres, French military efforts to conquer existing African states were intensified in all French colonies including Niger.