ABSTRACTThis article explores the impact of immigration on the social history of Derby, England, after the Second World War. In particular, it studies the changes in the city's religious culture associated with the decline of Christianity as the city's civil religion and the increased religious pluralism due to immigration. This local study challenges assumptions about the nature and timing of secularization, and the characterization of religion in late twentieth-century Britain as militant. As new communities from South Asia and the West Indies settled in Derby, their politicization resulted in a growing emphasis on their religious identity that countered interethnic conflict and fostered civil society. The Christian churches are an important part of this story as they found new ways of remaining relevant, sometimes in concert with members of other faith traditions. Between 1930 and 2000, Derby experienced a shift from a civil religion to an array of religions that were civil to each other and concerned for the good of society. Religion continued to play a constructive role in English society at the end of the twentieth century.