One of the powerful conventional images of pre-colonial Africa is that of a continent of more or less immobile ethnic groups, living since time immemorial on their ancestral lands, steeped in their traditional cultures. In this image, Africa appears like a mosaic, with clearcut ethnic boundaries, each sherd representing a different people cum language cum culture cum territory. Since a number of years, however, historians and anthropologists of Africa have insisted that this image is misleading. Most pre-colonial societies were characterised by mobility, overlapping networks, multiple group membership and the contextdependent drawing of boundaries. Communities could be based on neighbourhood, kinship and common loyalties to a king, but this did not absolutely have to include notions of a common origin, a common language or a common culture. Our own research on the West African savannah has also shown the enormous importance of mobility. Among the societies of southern and southwestern Burkina Faso, for instance, which several projects have studied, there is hardly a single village whose history has not been characterised repeatedly by the arrival and settlement of new groups and the departure of others. In some cases, we can even speak of systematic practices of multilocality.