But there was one in a small mining village in south Wales that she never forgot. In fact, her reaction to the disaster in Aberfan was said to be one of the biggest regrets of her reign.

A total of 116 children and 28 adults were killed when a colliery spoil tip collapsed, catastrophically engulfing a primary school and surrounding houses on 21 October 1966.

While Prince Philip, Lord Snowdon and the then prime minister Harold Wilson visited the scene the following day, the Queen waited eight days before going to the village near Merthyr Tydfil, arriving to comfort the community shortly after a mass funeral had taken place.

The delay in going to Aberfan attracted some criticism and years later the Queen's former private secretary, the late Lord Charteris, said he felt he had given her poor advice.

"We told her to stay away [from Aberfan] until the preliminary shock had worn off," he said, adding that it was the biggest regret of her reign.

But for those left mourning in the village there was nothing but love and respect for the Queen, who they felt helped them during their darkest hour.

"To come to Aberfan wouldn't have been appropriate," said Jeff Edwards, the last child to be rescued from the school, who the Queen always referred to as "the little boy with the blond hair".

"The trouble with any royal visit is that you have an entourage and it just takes over and the rescue work was still ongoing.

"To have her come down any earlier would have added to the utter confusion."

He said the tragedy clearly affected her and she was visibly moved as she walked down from the cemetery to a local house.

"When she went into that house she was really upset and she had to compose herself before she went on to meet the relatives and families who had lost children and relatives," added Mr Edwards, who went on to serve as an independent mayor of Merthyr Tydfil and council leader.

The Queen walked to Moy Road, the street that led to Pantglas Junior School, where mourners had gathered to meet her.

"She came across and spoke to us and I didn't think of her as royalty really," said Mary Morse.

Marilyn Brown, whose daughter Janette was killed aged 10, recalled: "You could see that she was quite emotional. You could see that she cared, you know."

At the time, the Queen had two older children - Prince Charles and Princess Anne - but also two very young children - Edward was just two and Andrew was six, a similar age to many of the children who died.

"To me that day, she didn't come as the Queen, our monarch, she came as a mother, to sympathise, to empathise, to really appreciate what everybody had been through that day," added Denise Morgan.

Marjorie Collins, whose eight-year-old son Anthony Wayne died in the tragedy, said the Queen's visit had helped the community more than anything.

"They were above the politics and the din and they proved to us that the world was with us, and that the world cared," she said.

Cardiff-born journalist Brian Hoey, who covered the Aberfan disaster for BBC Wales, said the world's media was there to capture the moment.

"I couldn't believe how sympathetic she was," he said.

"I knew she would feel sympathy because she had young children of her own by that time. She had Andrew and Edward who were both little children so she could sympathise and empathise with the parents who were there.

"But she was absolutely wonderful and they were talking to her, they were asking her questions and telling her what they felt and it was absolutely very endearing to see it."

The Queen's bond with Aberfan endured throughout her reign.

Elaine Richards, who lost her nine-year-old daughter Sylvia in the tragedy, said the Queen had promised she would return to open the new school when one was built.

She did keep that promise and went on to visit the village a further three times.

In fact, whenever she was in the area, her thoughts would turn to Aberfan.

In 1997, when on an official visit in Merthyr Tydfil, she asked how far away the village was.

"She was told only a mile away and she insisted a visit to Aberfan was included in the itinerary," said Mr Edwards.

At the time there remained outrage that the Aberfan Disaster Fund - set up to help bereaved families - had been raided by the government to pay for the removal of the remaining six slag tips looming over the village.

The National Coal Board - found to be responsible for the disaster - had refused to pay for the work.

"That visit was instrumental in the money coming back, the £150,000 which had been taken from the Aberfan disaster fund to pay for the tips to be removed, being repaid to Aberfan," added Mr Edwards.