 At the University of Oxford, he was also a lecturer in Middle and Later Roman History from 1969 to 1990, when he was promoted to a readership; he was promoted again in 1992, to a personal chair as Professor of Late Roman History.Matthews left both The Queen's College and the University of Oxford in 1996 to take up a professorship of Roman History at Yale University, where he was also John M. Schiff Professor of Classics and History from 2001 to 2014.Matthews was elected a Fellow of the Royal Historical Society in 1986, a Fellow of the British Academy (the United Kingdom's national academy for the humanities) in 1990, and a Fellow of the Society of Antiquaries of London in 1993.