'This article recovers a missing chapter in the history of the historical novel: the concerted reactivation of the genre within the culture of international Communism in the middle decades of the twentieth century. Rehabilitating the career of the Australian-born British Communist, Jack Lindsay, it folds his role as a theorist and practitioner of the historical novel into a transnational account of the genre’s mid-century revival. Between the convocation of the Popular Front in 1935 and the emergence of the New Left after 1956, the historical novel travelled the circuits of international Communist culture, transforming the practice of the novel and training the habits of historical attention we have come to know as ‘history from below’. In the rise of radical social history and of magical realism as the recognizable form of a new ‘world’ novel, the Communist historical novel played a crucial mediating role. Drawing on Lindsay’s private papers, this article reconstructs his place within the movement culture of British Communism, while a close reading of his last novel, Thunder Underground (1965), ties the genre he pioneered to the politics of socialist humanism and to the practice of British cultural Marxism. (Publication summary)