Applying a comparative perspective, this article argues that the current crisis of European Union integration cannot be resolved by member states either transferring additional competences to the EU level or strengthening the intergovernmental dimension of integration. The systemic character of the ongoing process is weakening the institutional structure, which affects both the institutions and their power relations. The European Commission (EC), once a highly independent supranational actor on the eve of the integration process in the 1950s, now faces growing competition from intergovernmental elements in the institutional balance. The theoretical approach of historical neo-institutionalism offers new, useful insights into this research area. The articles uses this theory to analyze the EC’s evolution since the time of its creation in the form of the High Authority of the European Coal and Steel Community, focusing on the links between the gradual changes in its internal structure and its institutional position.

Although the phenomenon of “path dependence” was initially present in the EC’s internal systems, the later development of its competences in the institutional balance provoked member states to limit the commission’s activities in the second half of the 1960s. First attempts were made mainly by appointing weak presidents, but the later reform of the EC’s internal structure, undertaken by Neil Kinnock in the beginning of the 21st centry, directed its further structural development as a more technocratic institution. Consequently, the EC was not able to pursue its aims effectively in preparing for its enlargement to include Central and Eastern Europe. The increased heterogeneity of the member states after the 2004–07 enlargement also weakened the EC’s position in the institutional balance, diminishing its traditional function as the “engine of integration.”