European private international law is by now based mainly on a large body of uniform rules such as the Regulations Rome I, Rome II, Brussels I, Brussels I bis. This significant legislative output, however, does not take place in a vacuum. Rules of private international law have been earlier (and still are) adopted at national, international and even European level in scattered regulations and directives. The recent plethora of private international law rules gives rise to issues of delineation and calls for some sort of ordering as gaps, overlaps and contradictions become flagrant. At the same time, the resulting interactions can offer new insight, ideas and even opportunities at a more theoretical level. This book gathers a collection of essays resulting out of a series of international seminars held in Lyon, Barcelona and Louvain-la-Neuve. During those seminars, young researchers selected in an open call for papers had the opportunity to discuss their views among themselves as well as with various specialists of the field, such as more senior academics, EU civil servants, national experts and representatives of other international organisations. The book offers the fresh views of those who will in the future shape the dialectic between the various sources of private international law and attempts to launch a discussion on the “living together” of legal sources. Two ranges of topics are addressed in the book: - firstly, the relationship between EU private international law and national law (substantial and procedural) and/or international law (international instruments of private international law or of uniform substantive law); and - secondly, the relationship between EU private international law and other aspects of EU law (internal market rules of primary law, harmonisation through secondary law and other pieces of legislation enacted in the realm of the area of freedom, security and justice).