There has been an organisational transfer from the European Union to the Energy Community, while, at the same time, the transposition of EU law into the contracting parties of South East Europe and beyond has also proceeded. Thus far, the Energy Community has been the subject of relatively few theoretical explanations. This study aims at introducing a new alternative one (rational choice-historical institutionalist explanation) in order to conceptualize the role of the Community. This article consists of three sections. The first section compiles and evaluates the theoretical literature regarding the Energy Community. The second section explores rational choice and historical institutionalism's potential to explain the Community's evolution. The third section deals both with the Community's impact on the EU's external energy policy and the Europeanization of energy policies of the contracting parties. Institutional improvements within the Community for better implementation results are foreseen as policy implications.