This article considers how Humphrey Jennings sought to represent the experience of modernity. While this concern runs through his career, we focus here on the two works which represent the fullest exposition of his ideas. Pandaemonium was a project that Jennings began in the late 1930s and pursued until his death in 1950. Posthumously published, this book consisted of a montage of original sources which documented the ways in which industrialization and modernization were experienced in Britain between 1660 and 1886. The film Family Portrait (1950) was made by Jennings for the Festival of Britain. While the ruptures and conflicts generated by industrialization build in Pandaemonium to a potentially revolutionary climax, in Family Portrait such discordant notes are underplayed and overwhelmed by an emphasis on political compromise, historical continuity and the common traits of the English character. We argue that both the radical, socialist view-point of Pandaemonium and the ‘social patriotism' of Family Portrait were characteristic of left-wing thought in the 1940s. Moreover, Jennings's perception of modernity as a distinctive social and cultural experience was shared by figures such as Raymond Williams, whose very different work during the 1940s and 50s was animated by similar concerns. By underlining the degree to which both were differently absorbed in tracing the cultural transformations wrought by industrial capitalism, we stress the need to recover a politicized mid-twentieth century perspective on modernity.