The city of Johannesburg lies at the centre of the largest urban conurbation in sub-Saharan Africa. In the past, this conurbation was known by the clumsy acronym ‘PWV’, which stood for the Pretoria-Witwatersrand-Vereeniging complex. Today, this urban region has the political status of a province and has been re-named ‘Gauteng’, a popular local name meaning ‘place of gold’. A province that is almost entirely urban, Gauteng is home to 7.3 million people: about one-third of the national urban population of 21.8 million.2 At the last census in 1996, the population of Johannesburg itself was about 2.6 million.3 In the national hierarchy, this placed the city of Johannesburg just after the largest city in South Africa, namely Durban (2.8 million) and marginally ahead of Cape Town (also about 2.6 million).\nAlthough Johannesburg is in most respects a modern industrial city, it nonetheless shares many of the demographic features of other African cities. For a start, its population has grown rapidly during the past half century. Although the population growth rate of Johannesburg is now slowing down, its population is still growing in absolute terms. In this respect, Johannesburg is similar to most African cities, particularly the larger ones, which grew rapidly during the twentieth century, especially during the post-colonial period (Becker and Morrison, 1995:110-116; Miller and Singh, 1994:68-70; Rakodi, 1997:32-39). The main difference, of course, between Johannesburg and most African cities outside South Africa was state control over urbanisation, which resulted in lower urban growth rates than would otherwise have been the case. Another feature of major urban centres in Africa, especially sub-Saharan Africa, is high levels of in-migration (Miller and Singh, 1994:72-74). Although the urbanisation of Africans in Johannesburg was curtailed by government policy for most of the twentieth century, we shall present evidence to show that in-migration contributed substantially to population growth. Finally, urbanisation in Johannesburg is also characterised by the dynamic of circular migration, a phenomenon that it shares with most African cities (Mabin, 1990; Potts and Mutambirwa, 1990; Prothero and Chapman, 1985; Standing, 1985). The study that we present here is an analysis of the relationship between urbanisation and settlement patterns of the African population in the area under the administration of the Greater Johannesburg Metropolitan Council. Specifically, our aim is to provide an overview of the rate of population growth in Johannesburg over the twentieth century, and the extent of in-migration and circular migration; also the way in which housing policy has shaped the relationship between urbanisation and access to different kinds of accommodation. In order to do so, we have conceptualised migration in two ways. The first is ‘in-migration’. By this definition, anyone who was born outside the Greater Johannesburg Metropolitan Area is regarded as a migrant or, to be more precise, an ‘in-migrant’. The second is ‘oscillating’ labour migration. This definition of a migrant is the one used in the last population census and includes people who live away from their homes in order to earn a living or to look for employment. We will refer to such migrants as ‘circular migrants’.