Management texts have long been prescriptive regarding management practice, recommending managers do this, and managers do that, to ensure greater and greater effectiveness. Only a relatively minor proportion of management researchers have gone into the field to observe just what managers actually do. Change management literature tends to be prescriptive regarding how organisations should manage change, and why some leaders are better than others. There is a relative paucity of empirical information discussing what effective change managers actually do. This paper aims to present empirical data from a longitudinal change management research study to develop an enhanced understanding of what managers do during major organisational change. The first part provides a comprehensive overview of the main empirical studies of ‘what change do managers do’ over the last fifty years. The more salient among these are explored in greater depth, with their strengths and weaknesses examined. The second part assesses the applicability of the conceptualised categories using data from the research project, by comparing what change managers actually do against what is espoused in the literature. An analysis is provided which examines each activity performed by the managers, classifying these activities in terms of the change management roles identified in the literature, assessing the weight given to each role in terms of time and frequency. This research finds that the literature is reasonably accurate in its espousal of the roles for change managers. It also finds that information handling is a significant component for both managers and change managers, yet the research literature gives little significance to this role.