This sets the scene for the study by identifying a narrative propounded by London church leaders and commentators from the 1830s onwards of decline in religious allegiance, defined in terms of attendance at places of worship, in the context of urbanization and industrialization. This was taken up and developed by most historians of religion for much of the twentieth century. However, following suggestive later-twentieth-century local studies of churches in London, and drawing on the resources and evidence of material culture, oral history, and social and economic history this study claims that when the evidence base for religiosity is broadened the narrative of decline in religiosity needs to be reappraised.