The book is a study of Gregory the Great, the pope who sent Augustine (of Canterbury) and his fellow missionaries to convert the heathen English to Christianity (597). Markus gives a full account of Gregory's life and work, his thought and spirituality, within the setting of the world at the end of the sixth century. At a time of catastrophic change in Europe, Gregory's work as pope stands on the threshold of medieval Western Europe. The book deals with every aspect of his pontificate, providing a major contribution to the study of late antique society.