The European Council is today an important and powerful institution in the EU. Starting as just informal meetings among the leaders of the European community in the 1960's, it has now developed and has become one of the seven institutions in the European Union. The study uses Historical Institutionalism as theory and process-tracing as method. Historical Institutionalism is providing the paper with the analysis tools. With critical juncture, positive feedbacks, path-dependency and sequencing as analysis tools the paper is explaining and analyzing the European Council from an historical institutionalistic perspective and also is identifying actors that are either promoting the progress of the European Council or are opponents of the progress...