The Prince of Wales has said he hopes conflict zones around the world copy the Northern Ireland peace process.
On a whistle-stop tour of Donegal in the Irish Republic - a year after his emotional trip to where his great-uncle Lord Mountbatten was murdered by the IRA in 1979 - Charles praised the people of the region.
“As I mentioned in Sligo last year the relationship between Britain and Ireland is now better than ever,” he said.
The Prince was speaking during a civic reception at Letterkenny Institute of Technology after spending more than half an hour on The Diamond in Donegal town with his wife, the Duchess of Cornwall, shaking hands with hundreds of well-wishers.
“And the relationship between the communities on this island has changed fundamentally since the peace agreement of 1998 this is as evident here as anywhere,” he said.
“The border is of the merest consequence and Co Donegal, Co Derry, or Londonderry, and Co Tyrone operate as a single economic entity to the great benefit of their inhabitants.
“So, I can only applaud the people of all three counties for proving that it is possible for communities that have been divided for so long to overcome their differences and create a peaceful and prosperous life together.
“I do so hope that the example you have set will be copied in other areas of the world that have suffered so much conflict.”
The day-long visit to Ireland is the latest royal bid to solidify transformed relations with the Republic.
The Prince’s symbolic step comes after the Queen’s historic visit in 2011, when she became the first British monarch to set foot in the country for a century.
Security was tight for the couple’s engagements, with two women protesting on the edge of Donegal town and about 30 republicans making their opposition known with placards a few hundred yards from Letterkenny IT.
Charles and Camilla also toured Donegal Castle, the Magee Donegal tweed factory and local artisan butchers McGettigans.
They also had a private visit to Glebe House, the home for nearly 30 years of renowned artist and friend of the Prince, Derek Hill.
The day trip ended in Glenveagh National Park and Castle.
Minister for Foreign Affairs Charlie Flanagan said the return visit by the royals marked Ireland and Britain’s 21st century relations.
“Last year, your visit was a powerful demonstration of our two countries’ shared focus on peace and reconciliation, with many elements in your programme also demonstrating 21st-century links between us - in education, in science and in many other walks of life,” he said.
“If I were to characterise your welcome visit today to Donegal, it might be one which marks our 21st-century friendship, and our ever-growing efforts to work together.
“Working together between Britain and Ireland. Working together north and south on this island. Working together across our open border, between neighbouring counties - indeed between good and friendly neighbours.”