A book series dedicated to the harmonisation and unification of family and succession law in Europe. The series includes comparative legal studies and materials as well as studies on the effects of international and European law making within the national legal systems in Europe. The books are published in English, French or German under the auspices of the Organising Committee of the Commission on European Family Law (CEFL). The Principles of European Family Law drafted by the CEFL are aimed at contributing to the harmonisation of family law in Europe. The first sets of Principles cover Divorce and Maintenance Between Former Spouses, Parental Responsibilities and Property Relations between Spouses respectively. This book focuses on Principles Regarding Property, Maintenance and Succession Rights of Couples in de facto Unions. The CEFL has developed a comprehensive and original set of rules which may be a source of inspiration for legislating the rights and duties of couples who have not formalised their relationship. In their provisions on specific issues, the Principles opt for workable solutions which aim to avoid unnecessary hardship and disputes. The Principles should be used as a frame of reference by policy makers and legislators.