Isaac Schapera 
Tribal Innovators [PDF ebook] 
Tswana Chiefs and Social Change 1795-1940

This book is a completely revised version of a study published in 1943. That study, entitled Tribal Legislation among the Tswana of the Bechuanaland Protectorate, dealt with the role of chiefs as agents of social change and, in particular, with the changes they brought about by making new laws. It described the various kinds of legislative process current among the Tswana, and reviewed systematically the content and scope of the many laws made, from the earliest known instances up to the time of writing (1942), in eight different chiefdoms or ”tribes”; it also stated, where possible, why those laws were enacted, and discussed how far they really succeeded in establishing new ways of life.