The Queen’s eldest son, Charles, 72, is now King.
He is this country’s longest serving heir to the throne and has carved out his own royal role over the decades.
In recent years he, and his wife Camilla, have made annual trips to Ireland where – they have aid – they wish to visit every county.
His several charities raise more than £100 million a year.
They include the arts, the built environment, responsible business and enterprise, young people, global sustainability and rural affairs.
His principal youth charity, the Prince’s Trust, helps disadvantaged and vulnerable young people, using practical support including training, mentoring and financial assistance.
It is seen as one of his greatest achievements.
He is patron of more than 400 organisations and carries out nearly 550 royal engagements a year.
As someone now in old age, having spent decades understudying for the top job, he described how he came to terms with his role, thus:
“I’ve had this extraordinary feeling, for years and years, ever since I can remember really, of wanting to heal and make things better.
“I feel more than anything else it’s my duty to worry about everybody and their lives in this country, to try and find a way of improving things if I possibly can.”
In the 1990s, he experienced turmoil in his private life, played out on a public stage when he split from the Princess of Wales.
He wed his shy bride, Lady Diana Spencer, on July 29 1981 at St Paul’s Cathedral and the couple had two sons – Prince William, born in 1982, and Prince Harry, in 1984.
But within a few years all was not well with the marriage.
Charles was having an affair with his former mistress, Camilla Parker Bowles, and Diana had turned to cavalry officer James Hewitt.
For the Queen, 1992 was her “Annus Horribilis” – the Waleses split, as did the Duke and Duchess of York, and Windsor Castle went up in flames.
In 1994, Charles admitted adultery on national television, speaking to his biographer, Jonathan Dimbleby, while Diana subsequently went on the BBC’s Panorama programme to give an interview in which she said there were three people in her marriage.
The message was clear – the third person was Mrs Parker Bowles.
In the early 1970s, Charles had met Camilla Shand on a Windsor polo field, and is said to have “lost his heart” to her almost at once. They embarked on an affair.
But when the prince joined the Navy, the couple spent long periods apart and Charles missed his chance and was heartbroken when Camilla married cavalry officer Andrew Parker Bowles.
He famously divorced his wife Diana divorced in August 1996.
In July 1997 he went public with his widely-known and reported relationship with Camilla, which dated back to the 1970s, when he hosted a lavish party for her 50th birthday.
A month later Diana died with Dodi Fayed, in a car crash in a Paris underpass.
The Windsors faced a backlash over their treatment of Diana and Camilla retreated into the background.
Their first public appearance together was outside the Ritz hotel in London in 1999, where photographers had been tipped off.
They wed in a civil ceremony at Windsor Guildhall on 9 April 2005.
Camilla became HRH the Duchess of Cornwall and established herself as a senior member of the royal family.
Charles was pictured with his sons, William and Harry, daughters-in-law Kate and Meghan, grandchildren and Camilla in a family portrait to mark his 70th birthday.
For his 70th birthday the Queen, who lobbied for him to succeed her as Head of the Commonwealth (it is not an inherited a title and a role she developed for herself), endorsed him as her heir and successor.
She described him as “a Duchy Original” and “a dedicated and respected heir to the throne to stand comparison with any in history – and a wonderful father”.
She added: “Most of all, sustained by his wife Camilla, he is his own man, passionate and creative.”
More recently she made clear she believed Camilla was suitable, in her eyes, to be Queen to his King.