This volume presents the composite character of the Cistercian Order in its unity and diversity, detailing the white monks' history from the Middle Ages to the present day. It charts the geographical spread of the Order from Burgundy to the peripheries of medieval Europe, examining key topics such as convents, liturgy, art, agriculture, spiritual life and education, providing an insight into Bernard of Clairvaux's life, work and sense of self, as well as the lives of other key Cistercian figures. This Companion offers an accessible synthesis of contemporary scholarship on the Order's interaction with the extramural world and its participation in, and contribution to, the cultural, economical and political climate of medieval Europe and beyond. The discussion contributes to the history of religious orders, and will be useful to those studying the twelfth-century renaissance, the apostolic movement and the role of religious life in medieval society.