In this book - intended for everyone interested in EU decision making - two main research questions will be answered. Firstly, what is the relationship between the European Council and the other EU institutions? Secondly, what are the various roles of the European Council in the EU decision-making process? The results of this research will show that European Council conclusions have been used extensively in this decision-making process, and this has increased considerably over time. Based on the analysis of European Council conclusions and legal texts a typology is created to provide an orderly picture of the European Council's various roles, such as the European Council as a political initiator, as an interpreter of the Treaties and as an appeals council.