The Prince of Wales is the nation’s longest serving heir to the throne, a position he has held since he was three years old.
With the Queen giving her blessing to Charles and the Duchess of Cornwall as a future King and Queen, it marks a significant milestone in the prince’s destiny and in his relationship with his mother.
The monarch, who has become the first British sovereign to celebrate a Platinum Jubilee, has called on the public to support the prince and the duchess when the end of her reign eventually marks the start of her son’s.
Charles himself will issue a statement on the Queen’s historic Accession Day on Sunday in honour of his mother’s record-breaking reign.
His future path to kingship had previously been boosted by the Queen, but never before has the monarch so directly referred to his future role as sovereign.
The tricky question of whether the prince would take on the non-hereditary role as head of the Commonwealth when monarch was resolved in 2018 when the Queen made a rare and public personal appeal at the Commonwealth Heads of Government Meeting in London for Charles to be chosen for the duty.
“It is my sincere wish that the Commonwealth will continue to offer stability and continuity for future generations, and will decide that one day the Prince of Wales should carry on the important work started by my father in 1949,” she said.
World leaders confirmed he would eventually succeed his mother in the symbolic role when king.
Then the Queen paid her a poignant tribute to the prince at a party to celebrate his 70th birthday the same year.
She described Charles as “a duchy original” and “a dedicated and respected heir to the throne to stand comparison with any in history — and a wonderful father”, adding: “Most of all, sustained by his wife Camilla, he is his own man, passionate and creative.”
The words served as a glowing queenly seal of approval for a future king.
The past 10 years have already seen a royal family in transition.
In 2013, Charles opened the Commonwealth Heads of Government Meeting (CHOGM) in Sri Lanka, representing his mother in the role for the first time.
Writer Catherine Mayer, who was given rare access to the prince, said the same year that he was “joylessly” increasing his royal workload and believed becoming king would be akin to “prison”.
Clarence House denied this was the case, saying this was not the prince’s view.
Mayer wrote that the prince was “impatient to get as much done as possible” ahead of succeeding his mother as monarch.
Charles has described how he wants to make the most of his position within the royal family.
He told US’s Time magazine: “I’ve had this extraordinary feeling, for years and years, ever since I can remember really, of wanting to heal and make things better.”
In 2016, the year she turned 90, the Queen called time on her overseas travels, leaving long-haul destinations to the younger members of her family, and late Duke of Edinburgh retired from public duties in 2017 at the age of 96.
In 2017, Charles began the practice of laying a wreath at the Cenotaph on Remembrance Sunday on behalf of the Queen as she watched from a nearby balcony instead.
He announced a major restructuring of his charities ahead of his 70th birthday in 2018, viewed as planning for the time when he will be king.
His role as future head of the Commonwealth was secured the same year, thanks to the Queen.
For the past three months, the Queen, now 95, has been on doctors’ orders to rest after spending a night in hospital for preliminary tests.
The pandemic has led to the nation’s longest reigning monarch turning her hand to virtual appearances instead.
At a Sandringham reception on the eve of her Accession Day, the Queen, whose husband Philip died in April, used a stick to rest on, but looked chatty and on form.
It was her first major in-person public engagement for 15 weeks.
Charles has dedicated decades of his life to royal duty and charitable work as he has carved out a role for himself as a king in waiting.
The arts, the built environment, responsible business and enterprise, young people, global sustainability and rural affairs have been the focus of his philanthropic work.
Inspired by his belief in harmony and sustainability, he has set up a host of charities, which raise more than £100 million a year.
His leading youth charity the Prince’s Trust helps disadvantaged and vulnerable young people, using practical support including training, mentoring and financial assistance, and is seen as one of his greatest successes.
As patron of more than 400 organisations, Charles carries out nearly 550 royal engagements a year.
The prince, who is known for his strong opinions, particularly on climate change and the environment, architecture and farming, has faced criticism in the past after accusations of lobbying government ministers on his views.
In the 1990s, he experienced turmoil in his private life, played out on a public stage amid his affair with Camilla Parker Bowles and his divorce from Diana, Princess of Wales.
In 1994, Charles admitted adultery on national television, speaking to his biographer, Jonathan Dimbleby, while Diana subsequently went on Panorama to give a television interview in which she said there were three people in her marriage.
Diana died tragically with her lover Dodi Fayed in a car crash in a Paris underpass.
Grief-stricken Princes William and Harry were only 15 and 12 years old, and the Windsors faced a backlash over their treatment of Diana, dubbed the People’s Princess in the aftermath for her charity work and charm.
Charles wed Camilla in 2005, and the pair have been married for nearly 17 years.