These three chapters are a version of lectures delivered at Cambridge on 22, 23 and 24 November 1993. The occasion was organised at Clare Hall by Dr Janet Huskinson with unfailing thoughtfulness. It was rendered gracious by the hospitality and by the participation throughout of the President, Sir Anthony Low. The panel of discussants chaired by Keith Hopkins – Peter Garnsey, Robin Lane Fox, Christopher Kelly and Rosamond McKitterick – have not only left me with food for thought for many years to come: they provided us all with a model, for our times, of commentary and disagreement that were as lively as they were courteous. The presence in the audience of so many friends and colleagues – Henry Chadwick, Ian Wood, Robert Markus, William Frend, Andrew Palmer, to mention only a few – guaranteed that the discussion ranged vigorously throughout the entire late Roman and early medieval period. Altogether, I present these chapters with a touch of sadness: they are, simply, the lees of the wine – what survives in print of an unusually vivid and humane occasion.

A shorter version of the first chapter had been delivered, in the previous year, as a Raleigh lecture of the British Academy (Peter Brown, ‘The Problem of Christianisation’, Proceedings of the British Academy: 1992 Lectures and Memoirs 82 (1993), pp. 89–106). The themes of that chapter, and of the two subsequent chapters, emerged in large part as a result of my work for sections of volumes XII and XIV of the Cambridge Ancient History.