The Investiture Controversy was a struggle for the right order in the world and marked one of the deepest turning points in the history of Western medieval times. It was a battle for reforms that had repercussions extending to the threshold of the present day. The author vividly and accessibly describes the dramatic struggle between the increasingly self-assured papacy and the monarchies of Europe, particularly the Empire under Henry IV and Henry V. Henry IV's journey to Canossa in 1077, at the height of the conflict between the spiritual and political powers of the papacy and monarchy, has left a deep imprint on historical memory. Both the fundamental demands and the theological-canonical justifications of the reformers, as well as the struggle between the two highest authorities, shaped the events of that time.