Following his exposure to the works of Marrou and Piganiol as an undergraduate, and shortly after joining All Souls College as a Prize Fellow, Brown travelled in Italy in 1957–8, doing research at the British School in Rome. During that time, he was especially influenced by the work of Santo Mazzarino, which provided a stimulus for Brown's earliest lectures at Oxford, on return from Italy in 1958. Other early influences were Norman Hepburn Baynes, William Frend and A. H. M. Jones.