The Principles of European Family Law drafted by the Commission on European Family Law (CEFL) contain models which may be used for the harmonization of family law in Europe. This book contains the Principles regarding Property Relations between Spouses. In these Principles, the CEFL has developed an all-inclusive set of rules for two matrimonial property regimes: the participiation in acquisitions and the community of acquistions. Both regimes have been put on an equal footing. Each matrimonial property regime, whether it functions as a default or as an optional regime is strongly connected with the rights and duties of the spouses and the possibility for them to make a marital property agreement. These issues have also been addressed by including two common Chapters on the General Rights and Duties of Spouses and on Marital Property Agreements which are to be applied regardless of which of the regimes applies.