Queen Elizabeth II on Sunday became the first British monarch to reign for seven decades, announcing her “sincere wish” that Camilla, the wife of her heir Prince Charles, should ultimately be known as queen consort.

Britain’s longest-serving monarch acceded to the throne aged 25 on Feb 6, 1952, following the death of her father King George VI.

She marked the historic date quietly at Sandringham, her estate in eastern England where her father died.

But in a major statement on the future of the royal family, the 95-year-old released a message to the nation, saying “it is my sincere wish that, when that time comes, Camilla will be known as queen consort”.

This means Camilla, now 74, would be crowned alongside Charles, now 73, and known to the public as Queen Camilla, royal experts said.

Charles said the couple were “deeply conscious of the honour represented by my mother’s wish”, which would accord Camilla the full title of a monarch’s wife.

He praised Camilla, saying: “my darling wife has been my own steadfast support throughout”.

The heir-to-the throne also paid tribute to the Queen’s “devotion to the welfare of all her people”, which “inspires still greater admiration with each passing year”.

The queen said she hoped that when Charles becomes king, the British people would give him and Camilla “the same support that you have given me”.

Camilla was long vilified for her role in the break-up of Charles’ marriage to Princess Diana.

Recognising the sensitivities, when the couple married in 2005, the royal family announced she would be known as princess consort after Charles became king.

But she has gradually won plaudits as the future king’s loyal wife and Londoners who spoke to AFP welcomed the plan.

“I think she’ll probably be successful, maybe surprise a lot of the British public,” said John Bishop, a 72-year-old property company owner.

“She comes over well, and I think she’s a great, great support for Charles,” said Angela Roberts, an 80-year-old retiree.

“He will need it, he’s got a difficult act to follow, hasn’t he?”

‘Historic reign’

Stressing the queen’s ongoing role, Buckingham Palace released a photo taken at Sandringham this week showing her working on one of her famous red dispatch boxes used for government business.

Behind her is a photo of her late father.

With the main Platinum Jubilee celebrations set for June, Prime Minister Boris Johnson said he was looking forward to “when we will be able to come together as a country to celebrate her historic reign”.

He also praised the queen’s “inspirational sense of duty and unwavering dedication”.

Four days of festivities are planned for early June, coinciding with the anniversary of her 1953 coronation, including a military parade and music concert, street parties, a nationwide “Big Jubilee Lunch” and a “Platinum Pudding Competition”.

During her reign, the queen has remained a constant through periods of huge social and political upheaval – a living link to Britain’s post-war and imperial past.

In her message addressed to the public signed “Your servant, Elizabeth R”, the queen renewed a pledge she first gave in a broadcast on her 21st birthday “that my life will always be devoted to your service”.

In September 2015, she surpassed Queen Victoria’s 63 years and seven months on the throne and, despite some health concerns over the past year, her latest message showed she is determined to continue her record-breaking reign.

After husband Philip’s death in April last year, the queen returned to public and official engagements, including hosting world leaders at the G7 summit.

She was forced to slow down on advice from doctors, however, after an overnight hospital stay in October sparked public concern.

Since then, she has largely stayed at Windsor Castle and made few public appearances.

But on Saturday, the queen held a reception for locals at Sandringham, reportedly her largest in-person public engagement since the autumn health scare.