The United Nations broadly defines a family as "any combination of two or more persons who are bound together by ties of mutual consent, birth and/or adoption or placement and who, together, assume responsibility for, inter alia, the care and maintenance of group members, the addition of new members through procreation or adoption, the socialisation of children and the social control of members" (Proinsias de Rossa - Social Welfare Minister's speech, February 14, 1995; Dail Debates, Volume 449 - The United Nations and the Irish Steering Committee of 1994 concentrated on a broad definition of the family as the fundamental element of society).

This definition is very broad and encompasses any sort of relationship where individuals assume the obligation to live together. This is done in order not to exclude anyone from forming part of the term "family".

The term "family" is found in article 23 of the International Covenant on Civil and Political Rights (ICCPR). Article 23(1) states that "the family is the natural and fundamental group unit of society and is entitled to protection by society and the state". Family is said to be natural and fundamental, yet, it does not state what constitutes a family.

However, sub-article 2 of the same article adds that "the right of men and women of marriageable age to marry and to form a family shall be recognised". Although there is no direct definition, indirectly the covenant seems to indicate that a family is formed by a marriageable union of a man and a woman.

Marriage and family are seen synonymous as well in article 10 of the International Covenant on Economic, Social and Cultural Rights (ICESCR). However, they still do not provide a strict definition of what a family is.

Can a family be equated to family life or family environment? The concepts of family life can be found in the European Convention on Human Rights (ECHR) and family environment is found in the Convention on the Rights of the Child (CRC) and the African Charter on the Rights and Welfare of the Child.

The CRC in its preamble states that a child should "grow up in a family environment". However, both conventions and the African charter do not define what constitutes family life and family environment. Yet, case law of the European Court of Human Rights (ECtHR) seems to point to the notion that family life includes also de facto families. In the landmark judgment of Marcks vs Belgium (1979), the ECtHR declared that family life between an unmarried mother and her child is created by the fact of birth itself.

Geraldine Van Bueren adds that "there is an automatic and immediate transformation of the biological bond into a legal one and this attracts the application of article 8 (of the ECHR)" (Child Rights in Europe, Council of Europe Publishing, 2007, 118).

In Boughanemi vs France (1996), the ECtHR stated that, even though there is no cohabitation, the bond between a parent and his or her child, whether such child is born in or out of wedlock, still constitutes family life.

The relationship between a parent and a child suffices as the fundamental constituent of family life.

The ECtHR declared that the relationship between two adults and their daughter who lived together but couldn't marry, because at that time divorce was not allowed in Ireland, constitutes, for all intents and purposes, family life as stated in Johnston and Others vs Ireland (1986).

Family life depends upon the existence of close personal ties.

The ECHR extends its protection under article 8 (the right to respect one's private and family life) to unmarried parents even if such non-marital relationship has been terminated as stated in Sommerfield vs Germany (2003).

Can relationships between children and grandparents also fall within the ambit of family life? In Price vs UK (1982), the ECtHR ruled that blood ties only are not enough to build family life between grandparents and grandchildren. In 2000, the ECtHR, in L vs Finland, made it known that the grandparental bond does not have the same significance as the bond parents have with their children.

Neil Ferguson et al state that the existence of family life needs to be seen from the child's and parents' perspectives. And he adds that in order to benefit from article 8's family life the content and the nature of the grandparental relationship needs to be studied (Grandparenting In Divorced Families, Bristol, 2004, 74).

In Cauchi vs Direttur tas-Sigurtà Sońčjali (October 10, 2005), the Court of Appeal stated that the test to assess the term "family" under the Social Security Act is one defined by cohabitation. Therefore, two unmarried cohabitating persons are deemed to be a "family" under the Social Security Act even though under the Civil Code they cannot qualify.

In a range of cases, the ECtHR stated that various factors may be decisive in deciding what amounts to family life such as whether the couple live together, the length of their relationship and whether they have demonstrated their commitment to each other by having children or by any other means.

It seems that the notion of family life is taken to embrace not only marriage-based relationships but also relationships which are de facto, that is, where parties are living together outside marriage as stated in the Yearbook of the European Convention on Human Rights 1994 Vol 37 (The Hague, 1996, 259).