Raffaele Pettazzoni (1883–1959), Professor of the History of Religions at the University of Rome and one of the leading historians of religions in the twentieth century, maintained a long correspondence with Herbert Jennings Rose (1883–1961), the gifted Canadian scholar who was Professor of Greek at St Andrews and is best known for his work in the field of ancient religion and folklore. These letters, spanning the years 1927 to 1958, bear witness to the close relationship between the two scholars and focus on two of Pettazzoni’s books, both translated by Rose: Essays on the History of Religions (1954) and The All-Knowing God (1956). They also shed light on Pettazzoni’s initiative to the foundation of the journal NVMEN (1954), and reveal Rose’s brilliant personality.