This report explores the distinct roles and functions of leaders and managers within a business organization, using Mark and Spencer as a case study. It examines various leadership theories and models, including Fiedler's Contingency Theory, Blake's Managerial Grid, and Drucker's Management by Objectives, to analyze their strengths and weaknesses in different situational contexts. The report also critically evaluates the impact of these theories on leadership and management practices within Mark and Spencer, highlighting their potential benefits and challenges.