This monograph brings together into one volume the cumulative results of eight replica and near replica case studies of managerial and leadership effectiveness, most of which were carried out in collaborative partnership with scholar-practitioners within a diverse range of British public, private, and third sector organizations. Subsequent multiple cross-case analyses have resulted in the emergence of a tested and refined 'generic model'. These research findings go against the grain of predominant discourse; they challenge many long held assumptions about the 'contingent' nature of management, and provide strong empirical support for the concept of the 'universally effective' manager within and possibly beyond the national context of the UK. The monograph is intended for use by professors and students in undergraduate and postgraduate programmes in management, organizational leadership, and human resource development(HRD), and also by critically reflective research-informed and evidence-based managers, HRD practitioners, and other HR professionals, who are particularly concerned with management and leadership development and/or with management culture change initiatives.