This case study, with a total observation time span of eleven years (1995-2006) examines the processes of organizational change brought about through corporate strategy change as well as the role of the adaptation process of leadership style to that transformation. For this purpose Procter & Gamble will be examined in depth, serving as a case study for this doctoral thesis. The research objective in this doctoral thesis is twofold. The first aim is to develop an adaptation process model which is able to explain the limiations as well as the potential of leadership style when adapting to a new corporate strategy. Furthermore, the model indicates some alternatives for a successful adaptation when considering the leader and the company. The second objective is to introduce the Leadership Style Requirement Model (LSR Model), which is going to be developed in this doctoral thesis, as well as the four Strategic Rationales by Johnson and Scholes. In a first step the model and the rationales will be explained separately. In a second step a model will be presented that combines both of them.