The importance of context has been well established in studies of leadership (Bryman, A. and Stephens, M. (1996). The importance of context: qualitative research and the study of leadership. Leadership Quarterly, 7, pp. 353–371; Pettigrew, A. and Whipp, R. (1991). Managing Change for Competitive Success. Oxford: Blackwell). However, recent reviews of shared leadership have tended to merge findings across commercial and non‐commercial settings, disregarding contextual differences in these distinctive domains. Acknowledging that the challenges of leadership may vary in different organizational contexts, this paper argues that a focused review of shared leadership in commercial organizations (COs) is needed. The authors thus systematically review findings from over twenty years of empirical research on the practice of shared leadership in commercial organizations, critically reviewing definitions, theoretical dispositions and measurement approaches adopted in the field, before evaluating the impact of shared leadership on performance in this context. Findings from commercial and non‐ commercial organizations are then compared, highlighting significant differences in the conceptualization of shared leadership in these distinct settings. Contributing to theory in this field, a framework is developed, mapping the landscape of current research in commercial contexts, revealing critical gaps in our present understanding of shared leadership processes. Consequently, a model summarizing a proposed research agenda for future studies is provided, highlighting the need for such research to focus on the interactions of individuals as they share in the leadership of their team.

Purpose To date, empirical research on shared leadership (SL) has been dominated by quantitative studies of antecedents and outcomes, frequently in simulated environments. Consequently, there have been few authentic accounts of how SL is practiced within organisational teams. Underpinned by shared leadership theory and leadership behaviour theory, this paper aims to provide a fine-grained view of the SL behaviours exhibited by team members over time, in five organisational teams in Ireland. Design/methodology/approach This longitudinal qualitative study uses critical incident technique, semi-structured interviews and participant diaries to explore SL behaviours emerging in five teams over time. Findings SL became widespread over time in each team, with almost all (96%) team members exhibiting SL behaviours. Ten different leadership behaviours were exhibited, indicating that SL permits a wide variety of leadership behaviours to be expressed. Some leadership functions were rarely or never fulfilled by team members (team composition, performance monitoring and resource allocation), suggesting that these leadership behaviours are not amenable to sharing. Practical implications This paper provides an insight into how SL could be used to increase the leadership capacity in team-based organisations. Originality/value This paper adds depth to the understanding of SL, revealing the specific behaviours underlying this approach, expanding our understanding of the micro-dynamics at play in SL processes.