By reconstructing the history of kings and clans in the Kivu Rift Valley (on the border of today's Rwanda and Zaire) at a time of critical social change, David Newbury enlarges our understanding of social process and the growth of state power in Africa. In the early nineteenth century, many factors contributed to the creation of new social relations  in the Lake Kivu region—ecological change, population movement, the expansion of the Rwandan state from the east, the rise of new political units to the west, and the movement of many population groups and their ritual forms through the area.  Newbury looks in particular at the role of clans in the establishment of a new kingdom on Ijwi Island in Lake Kivu.
Drawing on detailed ethnographic observations of the social and ritual organizations of Ijwi society, an extensive  body of oral data, and evidence from written sources, Newbury shows that the clans of Ijwi were not static formations, nor did the establishment of a royal family on the island emerge from military conquest and internal social breakdown.  Instead, clan identities changed over time, and these changes actually facilitated the creation of kingship on Ijwi.  Through a detailed examination of succession struggles, of local factors influencing the outcome of such struggles, and of specific clan participation in public rituals that legitimize royalty, Newbury’s study illustrates the importance of clan identities in both the creation of state power and its reproduction over time.