This thesis explores the experience of the historical and contemporary commercial manager, its rise and fall as an expert occupation and its rise again as potentially a new organisational profession in the project-led organisation. Despite their importance in such organisations, commercial managers often report not seeing their work as a site for innovation and being viewed as being impediments to the experience of other functions in cross-functional teams. Their main association, the IACCM, intends to improve the status of commercial managers through 'professionalisation'. However, historically, the commercial manager was of considerable status, in the firms of the late Industrial Revolution. They have been lost to the principal histories of British management, until now. How was the status of the occupation lost? This thesis considers the historical structuring of the occupation through analysis and interpretation of historical employment archives and the novel use of historical actor's own situations wanted advertising to reconstruct the experience of the historical commercial manager.The lived experience of contemporary commercial managers was investigated using Critical Incident Technique and phenomenological content analysis of first-person accounts of commercial managers successfully and unsuccessfully attempting to innovate within their routine work. The conflicts and scarcities of their position are key elements amongst the antecedents of insight that lead to commercial innovation. This thesis responds to Rickard's (2003) call for more realistic research into innovation and practical models of the actual practices of innovating people. Past and present are unified by an analysis of trait and ideological theories of professionalism. Through development of a framework for assessing progress in professional mobility projects, conditions for the fall of historical commercial managers are theorised and the status of modern commercial managers is analysed. Several key debates are also considered, such the rate of vertical integration in British firms.The limitation of the study in both its historical and contemporary parts is the availability of data and interpretive approach taken to it. Although the method by which data types were elicited and analysed is clear and repeatable, there is a limitation in the degree to which the data is representative, in terms of the degree of participation of commercial managers and the physical limits of the archive; interpretation can only be carried out on the data that actually survives. Further work is proposed and recommendations are made for supporting the professional mobility of modern commercial managers. Once again, commercial managers find themselves as a response to the concerns of capital and enterprise, yet will their putative institution be able to create the kind of collective mobility that was impossible for their historical forebears?