For the first time a majority of Stormont Assembly members have voted to legalise same sex marriage in Northern Ireland, but the law change will not happen due to a voting mechanism triggered by the Democratic Unionists.
The "petition of concern" tabled by the DUP at the outset of the debate in Parliament Buildings, Belfast meant the proposal could only succeed if a sufficient number of both unionist and nationalist MLAs backed it.
While not enough unionists voted yes, the slim overall majority (50.5%) in favour has nevertheless been hailed as a symbolic victory by campaigners for same sex marriage in the region.
It is the first time a majority has backed the proposal on what was the fifth occasion the issue has been voted on in the Assembly.
Following the signing into law of same-sex marriage legislation in the Republic of Ireland last week, Northern Ireland is now the only part of the UK or Ireland where civil marriage is denied to same-sex couples.
The issue divides public opinion in the region, with vocal campaigners on both sides of the argument.
While advocates claim same-sex couples are being denied the rights afforded to heterosexuals, a number of Christian organisations insist the institution of marriage should not be redefined.
A number of same-sex couples are currently seeking to overturn the Assembly's ban in the courts.
In the summer about 20,000 people marched in Belfast city centre demanding a law change.
In 2005 Northern Ireland became the first part of the UK to allow same-sex civil partnerships.
The four previous votes on gay marriage at Stormont would have fallen on a simple majority basis, regardless of whether a petition of concern was tabled.