The contribution of company law to the realization of the domestic market is still pending in many areas. The clarification of the structural components, followed by the development of company law in the international process, takes center stage of the study. Civil rights, adjustments to the law, the creation of supranational legal forms and the concept of a legislator competition in the European domestic market belong to this. The findings gained from this are then applied to the current core questions of the European company law: the development of international company law, the protection of creditors and the systems of managing publicly owned firms.