Until the 1990s, electricity policy in Germany showed a high legal and economic continuity. The German Energy Act as the regulatory framework of the electricity industry basicly didn´t change for more than 60 years after its passing in 1935. Due to the liberalization specifications of the European Commission to create a European internal market for energy, the traditional German energy supply system was fractionalized. The liberalization question resulted in the phalanx of the German electricity industry splitting into two groups: supporters and opponents. While the big interconnected firms saw their upcoming national and international expansion chances, especially the municipal companies, in particular, feared that competition could threat their existence. Until that time, the monopoly system was characterized by high electricity prices, big excessive production capacities and a fixation on large fossil and nuclear power plants. Additionally, the electricity industry protagonists showed a high resistance to modernization and innovation. The liberalization of the energy supply on all value added stages through the abolition of the old demarcation zones immediately created a completely new competition situation on the German electricity market. Conflictual constellations between the protagonists arose in a policy field, in which the company and association structures had not changed for decades prior. During that long period, strong cooperation relationships have been built between the electricity industry, the regulating authorities and the political decision-makers. On the interconnected companies level the liberalization led to a unprecedented market concentration. Their number decreased from nine to four. As a result of the liberalization and the changes of the market structure the association landscape finally erode as well. In parallel to that development, the red-green government coalition gained power in 1998, which pushed the electricity policy towards the overall objective of environmental compatibility of the electricity supply. Therefore, the year 1998 is the starting year for this doctoral dissertation as a strategic policy field analysis, which focuses on the protagonists of the electricity policy and their action motivations. The investigation period ends with the Bundestag election in 2009, so it includes three legislative periods in relation to the national level. Simultaneously, the increasing Europeanization of the policy field ensured the shift of decision-making power and growing conflicts between the national and the European policy level. During that time, the lines of conflict, policy processes and protagonist constellations mainly proceeded along the dominating trends of liberalization and the environmental compatibility of the electricity supply system and the resulting conflict of aims. However, the political and absolutely dominating trend during the investigation period has been the rising influence of the European policy level on the national policy field developments. Thereby, the European Commission has been the strategic centre of the Europeanization of the policy field, while the European parliament also continuously extended its influence.