In 1953, Brown took up a scholarship to read Modern History at New College, leaving in 1956. Most of his degree was "devoted to English History in its entirety and to the European High Middle Ages, from 919 to 1127", but in his final academic year, he undertook a Special Subject on The Age of Augustine, and was particularly influenced by the writings of Marrou and Piganiol. That Special Subject had a profound influence on Brown: "I was thrilled by the glimpse which both authors offered of the sheer resilience of a pre-Christian society and culture at the very moment of the triumph of the Christian church within the Roman empire. Institutions and powerful bodies of ideas, that I had known only in the medieval and post-Reformation periods — and many of which, in their modern form, still hung, like chill clouds, above the heart of any Irish boy, Catholic or Protestant — were shown to have originated first in a very distant, ancient world."