a Special Subject on him. Among the early students to follow Markus' special subject on Gregory the Great was Ian Kershaw. In the 1960s, Markus befriended fellow historian Peter Brown, with whom he established a close friendship. Along with Brown, Markus played a decisive role in establishing Late Antiquity as a distinct period in European history. His reading of William Frend The Donatist Church greatly influenced him. While Frend argued that the Donatists represented the aspirations of the Berbers of North Africa, Markus agreed with Brown that they rather represented the pre-Constantian uncentralised traditions of the African Church. In subsequent years, Markus studied the early history of Christianity as a force in the social and political history of ancient Rome. His first monograph, Saeculum: History and Society in the Theology of Saint Augustine (1970), saw Augustine as a dissenter from the triumphalism of the post-Constantinian Christianity. In his Christianity in the Roman World (1974), Markus subjected the social and cultural history of Christianity to further study, and examined how it came to be the state religion of the Roman Empire. Markus argued that the growth of Christianity was largely achieved through its gradual incorporation of classical values, which made it more acceptable to Roman elites. In 1974, Markus was appointed Chair of Medieval History at the University of Nottingham. By this time, he had established himself as leading authority on the history of the early Church. During his period at Nottingham, Markus contributed greatly making the Nottingham Department of Classics a leading institution in its field. He was President of the Ecclesiastical History Society from 1978 to 1979. Markus took an early retirement from the University of Nottingham in 1982. He would rater classify his early retirement as the best decision of his life apart from marrying his wife. He was elected a Fellow of the British Academy in 1985. From 1986 to 1987 he was a visiting scholar at the Institute for Advanced Study. He was Distinguished Visiting Professor at the Catholic University of America in 1988. Although retiring from university duties apart from a few guest lectures, Markus continued researching and writing. His The End of Ancient Christianity (1990) examined how Roman culture eroded from the time of Augustine to that of Pope Gregory the Great. Wolf Liebeschuetz has described The End of Ancient Christianity as Markus' masterpiece. It was followed by Gregory the Great and His World