Streitgegenstand und Rechtskraft

Subject-Matter and Res Judicata. The Prospects of an Autonomous Concept of Subject-Matter under the Brussels Ia Regulation. While the debate on the reform of the Brussels Ia Regulation is well underway, the concepts of lis pendens and res judicata have thus far received little attention, despite constituting some of the Regulation's core mechanisms. In fact, there has long been a structural mismatch between the autonomously defined »subject-matter« of a dispute - underpinning the rules on lis pendens and the grounds for refusal of recognition - and a concept of res judicata that remains determined by national law. This incongruence may lead to unsatisfactory outcomes, e. g. where the lis pendens rules successfully prevent parallel proceedings but the resulting judgment produces only a limited preclusive effect, creating the potential for (further) decisions that will be incapable of circulation within the EU. Against this background, the present article explores the prospects of developing an autonomous concept of subject-matter under the Brussels Ia Regulation. It advocates harmonization based on the doctrine developed by the ECJ in its interpretation of Art. 29 Brussels Ia. A more far-reaching harmonization - one which could include an extension of the rules on lis pendens - would also seem useful, but for now it appears unlikely to receive sufficient support.