Lake Kivu, located in the Eastern African Rift, in a dramatic volcanic scenery, has fascinated the local people, inspiring legends; the explorers of the nineteenth century, inspiring romantic reports; and the scientists of the twentieth
and twenty- fi rst centuries, inspiring limnological and geochemical research. For some, Lake Kivu is a “killer lake”, containing vast amounts of carbon dioxide and methane in its deep, anoxic waters, and it has been compared to Lakes Nyos and Monoun, whose eruptions caused massive animal and human death in Cameroon. Fortunately, methane gas exploitation can help to reduce the eruption risk and at the same time supply an important amount of energy for the bene fi t of local development. However, the management of the lake resources, including methane harvesting and  fi sheries, is complex, and particular care must be taken during gas exploitation in order to avoid any negative impacts on the ecosystem and the goods and services provided by the lake.  In this chapter, the history of research on Lake Kivu is summarized, and the major  fi ndings that resulted from expeditions by British, Belgian, American, and German researchers are presented.