This is a fascinating, three-dimensional picture of the politics, society and religion of medieval Europe, the age that had as its great theme the unity of Christendom. Maurice Keen examines tribal wars, the Crusades, the growth of trade and the shifting patterns of community life as villages grew into towns and towns into sizeable cities. He explores how Papal victories, by blurring the distinction between temporal and spiritual matters, eventually undermined the spiritual authority of the Church. And he discusses how the Hundred Years War escalated from a feudal dispute into a full-scale national conflict, until, by the mid-fifteenth century, changing economic and social conditions had transformed the unity of Christendom into merely a pious phrase.