This book focuses on the legitimacy of corporate power wielded by corporate groups, integrating legal doctrine, economic analysis, and theoretical approaches. It reassesses how corporate groups can maintain legitimacy whilst exercising corporate power.Corporate groups are a prominent commercial feature of many jurisdictions and present unique challenges. The book argues that when analysed through the lens of corporate social responsibility, a legitimacy deficiency emerges. This arises from a lack of historical debate, diluted control mechanisms, and inflated growth, utilising unique features of the corporate group. It explores how the magnified power of the corporate group presents acute challenges for corporate legitimacy. Data is utilised alongside current examples of corporate groups which identify structural architectural patterns. It explores new technologies such as Artificial Intelligence and blockchain as ways of attaining legitimacy. It presents methods of attaining legitimacy for the continued wielding of power to be held within corporate groups.This book spans several research interests under the corporate law umbrella. It will be of interest to traditional black letter company lawyers. Additionally, it will be of interest to those who have an interest in business and those who are interested in the role of technology.