Enda Kenny made history when he laid a wreath at commemorations in Enniskillen, Co Fermanagh - 25 years on from the IRA Poppy Day bomb that devastated the town. At the other side of Northern Ireland, the Republic's deputy prime minister, Tanaiste Eamon Gilmore, joined dignitaries at a similar event in Belfast.
Mr Kenny said Queen Elizabeth's visit to Ireland last year as guest of former president Mary McAleese had closed a circle of history and laid the foundations for much closer relations between the Republic and the UK for the future.
"This is a historic day both in reality and symbolically," said the Taoiseach, who laid a laurel wreath at Enniskillen's war memorial. "The visit of Her Majesty to Ireland last year - the first of a reigning monarch in 100 years - closed a circle of history and set in place the platform upon which future much closer relations between the peoples north south and the people of our two islands can actually happen."
During a day long visit to Enniskillen, Mr Kenny had a private meeting with some of those bereaved in the 1987 bomb, attended a religious service at St McCartin's Cathedral addressed by former Church of Ireland primate Lord Robin Eames and met with veterans from both the Irish and British armies.
The Taoiseach said the choice of Enniskillen was particularly significant given the atrocity that unfolded a quarter of a century ago. Twelve people died as result of the no-warning bomb blast at the town's war memorial as people gathered for the traditional remembrance service. No one has ever been convicted of their murders.
"I thought it was a privilege and honour actually to participate in the ceremony at the cenotaph," said Mr Kenny. "To be able to lay a wreath on behalf of the Irish government in respect of what happened here but also to attend at the Cathedral and listen to the power of the words of Robin Eames and to meet members of the families who lost loved ones - direct families members - 25 years ago in Enniskillen."
One of those Mr Kenny met was Joan Wilson, whose daughter Marie died in the bomb. She said the Taoiseach's visit was very important in the journey to peace and reconciliation. "We must all work toward that," she said afterwards. "He encouraged us."
There was only one apparent discordant note struck during the day of events when a man briefly called out a heckle while Lord Eames addressed the congregation inside St McCartin's.
Mr Kenny said he found the day "very powerful". He added: "Today is an important day symbolically and it's the start of building on the platform brought to a conclusion last year by former President McAleese and Queen Elizabeth and we hope to continue to build on that for the future."