Is a ban on marrying the sibling of one’s former spouse a violation of the right to marry under Article 12 ECHR? That was the issue before the Court in Theodorou and Tsotsorou v Greece  ECHR 611 [in French].
The applicants, Georgios Theodorou and Sophia Tsotsorou, were a married couple. In 1971, Mr Theodorou had married PT – Sophia Tsotsorou’s sister – with whom he had a daughter. In 2001, the Athens Regional Court dissolved that marriage and in 2004 granted the parties a divorce. In 2005, Mr Theodorou married Ms Tsotsorou in a religious ceremony – but in the following year, PT complained about their marriage to the public prosecutor’s office, arguing nullity on the grounds of kinship by marriage between the two spouses.
In 2010 the Regional Court annulled their marriage on the basis of Article 1357 of the Greek Civil Code, which prohibits marriage between persons related by collateral descent up to the third degree. In its decision, the Regional Court pointed out that the applicants were second-degree relatives by collateral descent and that Greek law prohibited their marriage for reasons of decency and respect for the institution of the family. Subsequent appeals were dismissed and they appealed to Strasbourg.
The Court said that it should be slow to substitute its own judgment for that of the domestic authorities because they were best placed to assess and respond to the needs of society – but the conditions for marriage laid down by national laws could not be left entirely to the discretion of states parties . In the present case, the applicants had a long-standing and permanent relationship that had continued after their marriage had been annulled in 2015 and they still lived together – but without enjoying any official recognition of their relationship .
As a general rule, limitations on the capacity to enter into marriage because of issues of consent, consanguinity or the prevention of bigamy were likely to be compatible with Article 12; however, other prohibitions preventing marriage between consenting and legally capable adults could raise problems . In the present case, the purpose of the impediment was not to prevent, for example, any possible confusion or emotional insecurity on the part of Mr Theodorou’s daughter from his previous marriage to PT, nor to prevent a confusion of relationships or degrees of kinship . Further, the Court attached particular importance to the European consensus on the absence of absolute impediments to marriage between former sisters-in-law and brothers-in-law. Of the states reviewed, only Italy and San Marino had introduced such an impediment to marriage and, even then, that impediment was not absolute .
When the applicants married on 28 May 2005 there had been no obstacles to their doing so: they had had a religious ceremony without any hindrance, the competent domestic authorities had not opposed the marriage, no-one had objected to the publication of their intention to marry and there was no evidence that the competent authorities had expressed any doubts before issuing them with a permit to marry [31 & 32]. The issue of invalidity had arisen only after the fact: until 29 June 2015, when the Court of Cassation dismissed their cassation appeal, their marriage had been effective de facto – so they had enjoyed legal and social recognition of their marriage for more than ten years . The Government’s arguments that “biological estimates” and the practical risk of confusion, and that there was “a social need for communication of family members with the outside world” were unconvincing .
The Court had already found that marriage was widely recognised as conferring a special status and rights on those who enter it:
“Protection of marriage is in principle an important and legitimate reason for differing treatment between married and unmarried couples … and marriage itself is characterised by a set of rights and obligations that clearly differentiate it from the situation of a man and a woman living together. States, therefore, enjoy a certain margin of appreciation when they provide for different treatment according to whether or not a couple is married, particularly in areas [such as] tax, pensions and social security. In the present case, it appears that the applicants are currently deprived of all the rights granted to married couples, which they enjoyed for ten years” .
The annulment had therefore been a disproportionate interference with the applicants’ right to marry and there had been a violation of Article 12 .
Footnote: in the West, (but, evidently, not in Eastern Christendom), canon law forbade one to marry a spouse’s sibling even if one’s spouse had died: a position that subsisted in England until the passing of the Deceased Wife’s Sister’s Marriage Act 1907. The Act caused considerable controversy at the time, not least on the part of the Church of England – as this contemporary article from the Spectator archive demonstrates.