More or less together : levels of legal consequences of marriage, cohabitation and registered partnership for different-sex and same-sex partners : a comparative study of nine European countries

Through the institution of civil marriage all countries in Europe recognise regulate different-sex couples. As a legal institution marriage can be characterised as a form of partnership between two persons that is created by a formal act of registration, and that results in a number of legal consequences (rights and obligations, both between the partners, and between the partners and others including the state). Since the 1970s a growing number of European countries have made a growing number of these legal consequences available to unmarried partners in informal cohabitation. This legal recognition of informal cohabitation has sometimes been restricted to different-sex couples, while sometimes same-sex couples have been included. Since 1989 several European countries have introduced registered partnership, a legal institution that is more or less analogous to marriage, resulting in some or almost all of the legal consequences of marriage. In some countries registered partnership has only been made available to same-sex couples, while others made it also available to different-sex couples. And since 2001 a few European countries have opened up civil marriage to same-sex partners.