The purpose of this book is to focus on the contribution of one of the most prominent scholars in the strategy field, Michael Porter, from both a practitioner, that is Chief Executive Officer (CEO), perspective, and from a research perspective. Using such a dual perspective may improve the relevance of strategy research for the business community. Four leading chief executives, two from European multinationals (Royal Dutch/Shell Group and Unilever N.V.) and two from important Dutch public organizations (the Port of Rotterdam and the Ministry of Economic Affairs), were invited to reflect on Porter's contributions to four levels of analysis: (1) business level strategy, (2) corporate level strategy, (3) regional competitiveness and finally (4) national competitiveness. Against this background, the book is structured as follows: Chapters 2 to 8 deal with the four mentioned levels of analysis from a dual perspective - theoretical and managerial. The two final chapters aim to find out how Porter's theories are related to each other and whether and how the different levels of analysis can be connected.