The King and NI: A young Charles III's first glimpse of Northern Ireland

King Charles III was just 12 years old when he arrived in Northern Ireland for his first official visit.

On 8 August 1961, the young prince and his family sailed into Carrickfergus, County Antrim, on board a "floating palace" - the Royal Yacht Britannia.

He travelled with his mother, the late Queen Elizabeth II, his late father the Duke of Edinburgh and his then 10-year-old sister, Princess Anne.

It was to be the first of 39 trips to Northern Ireland as heir to the throne.

His parents had arrived for a two-day tour, packed full of formal engagements at town halls and locals businesses.

But while the Queen carried out her official duties, the royal children were largely kept away from the cameras.

Instead, Prince Charles and his little sister had afternoon tea at a County Down estate and enjoyed a picnic on a private island, where a hungry Labrador stole their bodyguard's lunch.

Tight security measures have been a feature of royal visits since the start of the Troubles in Northern Ireland, but back in 1961, the Royal Family's schedule could be publicised days in advance.

The Belfast Telegraph published an almost minute-by-minute guide of the Queen's itinerary, pointing out the best locations to see the monarch's motorcade.

There was great excitement ahead of what was her first visit for seven years, and only her third tour as reigning monarch.

In a rain-soaked Carrickfergus, an armada of little boats owned by well-wishers greeted the Royal Family, while hundreds of cheering spectators lined the town's harbour.

The Queen and the Duke disembarked for a tour of Carrickfergus Castle, but unlike their parents' itinerary, the younger royals' travel plans were not pre-announced.

"The children's destination had been kept secret at the Queen's wishes, right until the last minute," the Belfast Telegraph reported.

Prince Charles and his sister were brought ashore at Belfast and driven to Rademon Estate on the outskirts of Crossgar, County Down.

The 500-acre estate was then home to the aptly-named King family who were long-standing friends of the Windsors.

James Osborne King was a prominent estate agent and his wife, the Hon Elizabeth Patricia King (née White), was a childhood friend of Queen Elizabeth.

The Queen was also godmother to the couple's eldest child, 14-year-old Elizabeth Lavinia Sarah King.

Mrs King was descended from the Spencer family, sharing ancestry with Lady Diana Spencer - the future first wife of the young Prince Charles.

She was a first cousin of Lady Diana's father, the 8th Earl Spencer, but her family link to the Windsors goes back further.

Mrs King's mother, Lavinia Emily White (née Spencer), had been a lady-in-waiting to the late Queen Mother while she was the Duchess of York.

At Rademon, Prince Charles and his sister were joined by their parents for afternoon tea hosted by the Kings.

The following day, the Queen visited Belfast City Hall and Harland and Wolff shipyard but, reportedly, she did not believe her children would enjoy either event.

So instead, it was arranged that the prince and princess would go for a picnic on Strangford Lough, accompanied by Mr and Mrs King's three young children.

Sir Richard Pim, a retired inspector-general of the Royal Ulster Constabulary, was entrusted with sailing the children to Pawle Island - a small, uninhabited land mass off the lough's western shore.

Few people spotted the heir to the throne tucking into his packed lunch, but in the days that followed, "scores of holidaymakers" flocked to the island to explore the royal picnic spot.

Twenty years later, ahead of Prince Charles's wedding to Lady Diana, Sir Richard regaled the Belfast Telegraph with his memories of the Pawle Island picnic.

"I had brought Bracken, my Labrador, with me and the prince had his detective with him, a big fellow who must have been all of 20 stones," Sir Richard recalled.

"The detective decided he would go and find himself some beer and he went off, leaving his lunch on the stone where he had been sitting.

"Bracken, as soon as his back was turned, promptly went across and ate it."

Sir Richard said the young prince found the case of the stolen sandwiches "very funny" and the pair laughed about it when they met again in later life.

The 1961 visit was the King's only childhood trip to Northern Ireland and 18 years passed before he came back for a second tour.

During that period, the security situation in Northern Ireland deteriorated markedly.

The Troubles began in the late 1960s and Prince Charles was 31 years old by the time he returned to Northern Ireland in 1979.

He arrived three months after the IRA killed 18 soldiers in a bomb attack at Narrow Water, County Down.

The paramilitary group also killed his own great uncle and beloved mentor, Lord Mountbatten, in a bombing in the Republic of Ireland on the same day.

Prince Charles spent his 1979 visit meeting soldiers at various barracks close to the border, which had been the target of regular IRA attacks.

The peace process began to take hold in the 1990s and Prince Charles soon became a regular guest of Northern Ireland and an occasional visitor to the Republic of Ireland.

At a St Patrick's Day dinner four years ago, he revealed his lifetime ambition to visit all 32 counties on the island of Ireland.

In a speech to guests, he said he had already ticked 15 off the list at that stage.

"I am quite determined, before I drop dead and finally lose my marbles, that I should get around to the remaining 17," he added.