Although this work is a study in the history of one of medieval England's most famous corporations, my greatest obligations have always been to individuals. First and most obviously, this book owes its very existence to the labours of 123 monks who entered the religious life at Durham between 1390 and 1446, men whose activities form the primary subject of the following pages. What they would have thought of this retrospective and inevitably distorted description of their monastic community I hesitate to think; but they might have derived some consolation from the knowledge that I personally find their lives much more mysterious now than on the day I first began to look at the voluminous records they have left to posterity. In many ways a twentieth-century historian is singularly ill-equipped to understand the personal passions and aspirations of a late medieval monk. I must, in other words, have often failed in my desire to understand rather than to judge the monks of Durham. Nevertheless, to my surprise and against my initial expectations, I have come to respect the aims of the late medieval community of Saint Cuthbert more rather than less during the many days in which I have kept their posthumous company. For myself, and I hope for some readers of this book, their traditional offer of assistance still retains some validity: ‘Vestris nostra damus, pro nostris vestra rogamus’.