This paper is a case study in the wartime evolution of tactical doctrine. Besides providing a summary of German Infantry tactics of the First World War, this study offers insight into the crucial role of leadership in facilitating doctrinal change during battle. It reminds us that success in war demands extensive and vigorous training calculated to insure that field commanders understand and apply sound tactical principles as guidelines for action and not as a substitute for good judgment. It points out the need for a timely effort in collecting and evaluating doctrinal lessons from battlefield experience. --Abstract.