The 316th anniversary of the Battle of the Boyne was commemorated in at least one venue in the Republic as well as 18 others across Northern Ireland.
Áras an Uachtaráin was the location for a cross-community garden party for some 380 guests, hosted by President Mary McAleese and her husband, Martin, to mark the Twelfth.
Since her election in 1997 the President has evoked a theme of bridge-building.
While the Twelfth was a day more celebrated by one tradition, she said yesterday she was trying to broaden it and make it an occasion that everyone could be part of, like a carnival. "It shaped our history, it changed our history. It is a day we could surely learn to share," she said at the party, which she hosts each July 12th.
The two governments were pushing to restore partnership government to the North, she told guests. "I hope that political leaders will find the confidence, the courage and the determination to work together to make Northern Ireland's name soar at home and abroad for all the right reasons."
Guests at yesterday's event sipped wine and stout or tea and coffee, nibbled on canapes and saw a living history display of a battle camp typical of the 1690s, with actors playing the role of Williamites and Jacobites.
Musical entertainment was provided by the Drogheda Brass Band, traditional singer Brian Mullen and flautist the Rev Gary Hastings from Westport Church of Ireland parish.
The new speaker of the Northern Ireland Assembly, Eileen Bell, who described herself as "cautiously optimistic" about the future for the North, was among the guests.
So was Billy Murray from Pro-Kick Kickboxing Club on the Hollywood road in East Belfast, who presented Mrs McAleese with a picture, a graphic illustration by photographer Daryl Campbell, of herself wearing boxing gloves.
Their club was honoured when someone as important as "the President of Ireland visited our humble abode, just a corrugated iron building", he said.
Their next goal was to get her to attend their "Kickmas Special" a two-hour kickboxing extravaganza held every Christmas and televised by Eurosport.
Another guest was Tommy Bradshaw, who retired in June as a houseman at the Áras, where he had responsibility for the furniture. Mrs McAleese presented him with a plaque to commemorate his 37 years as an OPW employee.
