St Patrick's Day celebrations take place across Northern Ireland
Thousands of people have attended St Patrick's Day parades and festivities in towns and cities across Northern Ireland.
The Belfast parade began from the city hall at noon and made its way to Custom House Square for a free concert.
Parades and celebrations were also held in Londonderry, Armagh, Newry, Enniskillen, Omagh and Downpatrick.
For the first time, Stormont was among landmark buildings "going green" in honour of Ireland's patron saint.
Derry City Council had promised a "kaleidoscope of colour and culture" during its celebrations, with a free family fun day in the city and a carnival parade set off from the council's headquarters at 14:30 GMT.
The Archbishop of Canterbury, Justin Welby, was the guest of honour in County Down, where he took part in a service at Saul Church - built in 1932 to commemorate St Patrick's first church in Ireland.
The archbishop then set out on the pilgrimage walk to Downpatrick, where he laid a wreath at St Patrick's grave before joining a parade through the town.
Armagh's five-day St Patrick's Day festival culminated in a carnival procession through the city centre on Tuesday, which began at Palace Demesne at 13:00 GMT.
Earlier, the leader of the Catholic Church in Ireland, Archbishop Eamon Martin, delivered the homily at Saint Patrick's Cathedral, Armagh.
"All over the world today people of many creeds, languages and race are celebrating our national saint, Saint Patrick," he said.
"It is a testimony to the tremendous outreach to the rest of the world that Ireland has had over many centuries."
Newry's parade began at noon outside The Quays shopping centre and was followed by live music, Irish dancing and street theatre in the city.
Enniskillen's celebrations started at 13:30 GMT with a family fun day at Broadmeadow, followed by a parade through the County Fermanagh town from 15:30 GMT.
Omagh hosted a parade followed by an open-air concert, and the festivities kicked off in High Street from 13:00 GMT.
Elsewhere, in the Republic of Ireland, thousands of people attended parades, with the largest event taking place in Dublin where the comedian Brendan O'Carroll led participants as Grand Marshal.
Irish President Michael D Higgins and his wife Sabina attended the Dublin parade.
There were various events in Cork, Limerick, Galway, Waterford and many other towns and villages.
Meanwhile, in England, the Duke and Duchess of Cambridge were guests of honour at the annual St Patrick's Day Parade by the Irish Guards in Aldershot.
The Duchess handed out shamrocks to officers and guardsmen at Mons Barracks.
However, she struggled to pin a sprig on the collar of the regiment's mascot Irish wolfhound, Domhnall, as it kept falling off.