Prince Charles and the Duchess of Cornwall are attending special dinner in the Irish Embassy in London to mark the start of St Patrick's Day festivities in the UK.
Ambassador Adrian O'Neill welcomed the Royal couple to the Embassy.
The event is also being attended Tánaiste and Minister for Foreign Affairs Simon Coveney, as well as leading figures from the worlds of politics, culture, the media and the wider Irish community in Britain.
During a speech ahead of the dinner, Prince Charles said he had faith the friendship between Ireland and the UK would endure for generations as he vowed to visit all 32 counties on the island.
"With threads drawn from every part of Ireland, and from every walk of life, those who traversed the Irish Sea, who stitched together the fabrics of our societies and made us all the stronger for it.
"From Kintyre to Kilburn, the influence of the Irish diaspora on the arts, culture, business, academia, fashion and sport here in the United Kingdom has been as profound as it is immeasurable.
"And Ireland also offers its traditional hundred thousand welcomes - céad míle fáilte - to so many British people who have made their home across the water or who travel there to experience the warmth and beauty of your country.
"Above all we are friends, we are partners and we are the closest of near neighbours, bound together by everything that we have in common - and by just how far we have come together."
Titled Friends and Neighbours - A Celebration of UK-Ireland Relations it is designed to celebrate ties between the countries now and in the future.
Music will be performed by Eimear Quinn and Seána Davey while actor Adrian Dunbar will read a poem by Derek Mahon.