It was a marriage that created one of the most powerful political dynasties in Ireland in the 18th century and now it's to be commemorated with an event in Co Waterford to mark the tercentenary of when two aristocratic families were united.
Sir Marcus Beresford, the Marquess of Waterford was married to Catherine Power on the grounds of Curraghmore House near Portlaw in Co Waterford and the 300th anniversary of the event will be marked this weekend when the country estate opens its gates to the public.
According to local historian Julian Walton, the marriage united two families and two estates from opposite ends of the country and produced what was effectively, by the end of the 18th century, the most powerful political dynasty in Ireland.
"On July 16th, 1717, Catherine was married to an Ulster cousin, Sir Marcus Beresford of Coleraine, Baronet, whose ancestor had come to Ireland over a hundred years previously as an official of the Plantation of Ulster. It was his 23rd birthday; Catherine was aged 15 and a half," he said.
“Sir Marcus was created Earl of Tyrone in 1746, and after his death Catherine successfully claimed the title Baroness la Poer in right of her medieval ancestors. They died in 1763 and 1769 respectively and are commemorated by a huge monument in Clonegam Church in Portlaw.”
Mr Walton, who will give a lecture entitled '16th of July 1717: A Marriage that changed Irish History?' pointed out that Curraghmore House has remained in the family for at least six centuries and has been the seat of the Beresfords, Marquesses of Waterford for the last 300 years.
"During their reign, the great courtyard was built to the design of John Roberts. It is the biggest in Ireland and rivals that of Blenheim Palace in Oxfordshire. The room over the entrance hall, the medieval tower, was redecorated at this time, with stucco work by the Lafranchini brothers.
“Marcus and Catherine had a large family – of their fifteen children, nine survived to adulthood, three sons and six daughters. When you enter the outer hall at Curraghmore, your eye is immediately caught by the huge group portrait that occupies most of the left-hand wall.
"Painted in about 1760 by John Astley, it depicts the ageing Sir Marcus Beresford, Earl of Tyrone, and his wife Lady Catherine Power, surrounded by their nine children, all now well into adulthood," said Mr Walton, adding that Lady Catherine later created a magnificent shell house in the grounds.
The opening up of Curraghmore House and Gardens to the public is part of the annual Comeraghs Wild Festival and among the other events scheduled for the house is a lecture by historian Ken Nicholls on The Powers of Curraghmore.
Other events include a dramatisation of Jane Austen's 'Pride and Prejudice' performed by Chapter House Theatre Company on the front lawn with tickets available from Curraghmore and from Garter Lane Arts Centre in Waterford.
For more on the 300th anniversary celebrations, please visit to www.curraghmorehouse.ie