This article presents the implemented policies of the European Union in the broader field of energy and provides a picture of the Union's strategy on energy related issues. A brief historical background is provided, covering the period from the beginning of the Union's creation in 1951, when coal was considered as the heart of its economic growth, up to 2012. Policy development principles, as well as the consultations that take place before the proposal of each option are also discussed. Implemented policies are classified into seven broad categories: Renewable Energy, Energy Efficiency and Savings, Internal Energy Markets, Security of Energy Supply, Environmental Protection, Nuclear Energy and Research and Development. For each category, an introduction covering important milestones towards its development is followed by the presentation of the relevant policies and a description of their purpose. (C) 2013 Elsevier Ltd. All rights reserved.