The ninth President of Ireland, Michael D Higgins, has been inaugurated at Dublin Castle.
Hundreds of dignitaries, including the first and deputy first ministers, attended the ceremony on Friday.
The veteran politician was sworn in for his seven-year term in front of Taoiseach Enda Kenny and Chief Justice Susan Denham.
Mr Higgins took over from Mary McAleese who said an emotional farewell on Thursday after 14 years in the role.
The new president's wife and children attended the ceremony.
Mr Higgins arrived at the state apartments in the castle before 12:00 GMT for a service of prayer attended by members of all major religions to mark the start of the ceremony.
As well as the blessing, there was a moment of reflection to mark the humanist philosophy and secular aspects of Irish life.
During his election campaign, Mr Higgins, 70, spoke about the need to be more inclusive and also suggested the Presidential Oath of Office could be modernised to support that idea.
At the inauguration, the taoiseach requested the chief justice to read the Declaration of Office to Mr Higgins, followed by a formal signing in St Patrick's Hall.
After the ceremony, the Presidential Standard, blue with a gold harp, was hoisted above Dublin Castle and a 21-gun salute fired from the grounds of Collins Barracks a mile away.
The president was then escorted by motorcycle outriders to Aras an Uachtaráin, the president's home, where he hosted a lunch for 100 people.
Mr Higgins follows President McAleese, widely praised and heralded for her two terms in office and her theme of building bridges with communities across the Republic and Northern Ireland.
In his election speech, the former Labour Party politician vowed to lead the country in a necessary change in thinking in society and away from values based on wealth.
Mr Higgins, who secured more than one million votes, said his seven-year term would be defined by efforts to turn inclusion into reality.