This thesis examines the principle of Member State liability for breaches of European Community law committed by a national court adjudicating at last instance as established in the European Court of Justice's ruling of September 2003 in Gerhard Köbler v. Republic of Austria (C-224/01). It focuses on the ECJ's assessment in the case of the various approaches to Member State liability for judicial breaches under the national laws of the (then) fifteen EU Member States and extends the analysis to an enlarged Europe of 27. In an attempt to verify the Court's conclusions, namely that the concept of State liability for judicial breaches constitutes a common principle that has been accepted in most EU Member States, the thesis embarks on a comparative analysis of the prevailing national legal concepts in the area of State liability for judicial breaches. The categorisation of the different systems into four groups allows for the creation of a general taxonomy of the various national approaches to the question. An in-depth analysis of one national system per category then sheds light on the general concepts of public liability in the 27 Member States. The prototypes representing the four groups are the United Kingdom, Austria, France and Belgium.  Apart from the analysis of the framework and composition of the respective State liability regimes, special attention is directed to the interaction of the Köbler-principle on the Community level with the effective framework of State liability in the national prototypes. Against this background, the thesis provides a general reflection on the substantive and procedural difficulties arising in the course of the application of the Köbler-principle under each national remedial framework. In doing so, several issues are addressed, including the impact of liability à la Köbler on the principles of legal certainty and the impartiality of the judiciary, as well as the question of a possible violation of the principle of res judicata. Furthermore, the study addresses the claim that Köbler triggers the development of an indirect appellate procedure to the ECJ giving it the role of a 'quasi-final court of appeal'. In addition, the thesis seeks to unravel past and present problems of communication between the ECJ and the national supreme courts and discusses a possible change from the ECJ's traditional cooperative approach towards incompliant national supreme courts to a more assertive stance which suggests that non-compliance by the national court in question, with its obligation to make a reference for a preliminary ruling under Article 234(3) EC, might incur the liability of the Member State in question.