St Edmund's Abbey was one of the most highly privileged and wealthiest religious houses in medieval England, one closely involved with the central government; its history is an integral part of English history. This book (the first of two volumes) offers a magisterial and comprehensive account of the Abbey during the thirteenth century, based primarily on evidence in the abbey's records (over 40 registers survive). The careers of the abbots, beginning with the great Samson, provide the chronological structure; separate chapters study various aspects of their rule, such as their relations with the convent, the abbey's internal and external administration and its relations with its tenants and neighbours, with the king and the central government. Chapters are also devoted to the monks' religious, cultural and intellectual life, to their writings, book collection and archives. Appendices focus on the mid-thirteenth century accounts which give a unique and detailed picture of the organisation and economy of St Edmunds' estates in West Suffolk, and on the abbey's watermills and windmills.