Same-sex marriage has now become legal in the Republic of Ireland, after new legislation came into effect on Monday.
The law was passed after a referendum in May, when the Irish state became the first in the world to legalise same-sex civil marriage by popular vote.
It is not yet known when and where the first same-sex wedding will be held.
But the first people to be affected are same-sex couples who have already wed legally abroad. Their marriages are now automatically recognised by the state.
'Rights and protections'
They include Orla Howard and her wife Dr Grainne Courtney, who were married in the United States in May 2013.
The couple have been in a relationship for the last 13 years and live in Dublin with their two grown-up daughters.
"It's a terrific moment, because our marriage will be the same as any straight couple's marriage from Monday morning," Ms Howard told BBC Northern Ireland.
"It will bring all of the rights and protections that marriage brings, from the constitutional point of view, to our family and that's one of the key things for us."
Same-sex couples who are seeking to wed for the first time will be able to do so from Monday onwards, but it is not yet known who is in line to make legal history by marrying a person of the same sex in a Republic of Ireland ceremony.
The first newlyweds are likely to be couples who had already applied to register a civil partnership over the coming hours or days, but who now have the option to convert this into a marriage application for the same date.
Registrars have been contacting couples who fall into this category to find out their preferences.
People who are already in a civil partnership in the Republic of Ireland can now also choose get married, but they must give at least five day's notice of their intentions to a civil registration office.
Civil partners who do not wish to get married will remain as civil partners, their legal status will not be affected by the new law.
However, new applications for civil partnerships are no longer being accepted.
The Marriage Act 2015 only applies to civil marriage, and no Irish church or religious organisation that objects to the new law will be forced to perform same-sex marriage ceremonies.
The Catholic Church and other Christian organisations had campaigned against the legislation, arguing marriage should only be between a man and woman.