This book is an approach, in the wider theoretical considerations on scientific research and study, of issues relating to energy resources and energy security and, at the same time, it is a case study on Eastern Mediterranean energy security. The Mediterranean has been known since ancient times as a large semi-enclosed sea, surrounded by more than two states as it lies between three continents: Europe, Asia and Africa. However, developments in the 21st century have necessitated viewing it conceptually as a distinct "new" region with specific characteristics. Comprised by Cyprus, Egypt, Greece, Israel, Lebanon, Libya, Syria, Turkey, Italy the region is assuming increased significance in world affairs. More specifically, the region of the Eastern Mediterranean is currently of vital importance for the EU, due to several prospects and challenges, such as migration flows, energy, security and sustainability of the region. The individual objectives are the recognition of energy actions and resources, forms of energy, energy security and in general, all actions at the energy level mentioned in the specific area. Research this study will focus on the qualitative method to the subject. The structure of the present study was developed as follows: The Preface provides a general presentation of the topic. The first chapter presents an overview of eastern Mediterranean and energy issues. The second chapter reports on energy resources and it focuses on energy security and its basic principles. The third chapter is about energy and security. The fourth Chapter offers discussion on European Union's energy policy development and on the EU interests, strategy and policy regarding the Eastern Mediterranean region. The fifth chapter presents the changes in the East Mediterranean energy map and data on geopolitical chessboard. The last chapter presents the conclusions. A useful tool in completing this study was the understanding of the delicate ethnocultural and religious synthesis of the region, the current challenges and underlying controversies, considering the interlinked nature of interests and the importance of cross-border affiliations. All the findings of the study demonstrate certain dimensions of a reality, which are expected to be dynamic, creating risk but also future opportunities. The main finding of the study points out not only the strong correlation between energy, power, economics and politics but also the increased dependence of the latter two on the former, thus creating a hotbed of tensions, rivalries, and conflicts every time the existing relationship between economy and energy are destabilized. The shifting to energy sources, which are safe and eco-friendly, is a one-way process, the only means of survival and safe development for humanity. Generating energy based on economic, safe, cost-efficient and renewable criteria is the current ecological and technological challenge if, firstly, the vast interests in the energy sector are dealt with successfully. Finally, this book will be of key interest to scholars and students, for researchers in the fields of Energy Economics, Policy, and Security, Energy Law, Business, Regulation and Policy, Geopolitics, who aim to have a better understanding of the current trends or research in the relevant fields, for professionals in EU politics and foreign policy, energy policy and security, and more broadly to security studies, European politics and international relations and newcomers in the profession of energy security, and for policymakers who intend to apply the collective knowledge included into this volume into policy and decision -making.