A month ahead of her 75th birthday, the Princess Royal is thought to be planning a gradual reduction in her workload at 80 before finally fully retiring a decade later.

A source close to the Princess Royal revealed: “She has said her plan is to push on (with work) until she is 80, then start winding down a bit, and then copy the (late) Duke of Edinburgh and wind down completely at 90.”

Prince Philip famously retired from public life in 2017, aged 96, completing his final solo engagement at Buckingham Palace by taking the salute from the Royal Marines in heavy rain after 64 years as their captain general.

The source told The Times: “The head of state has to go on but the princess is in a position where she can wind down and say, ‘I’ve done my bit’, just like the Duke of Edinburgh did.”

The Princess Royal has firmly rejected all attempts to mark her 75th birthday next month with anything more than a single commemorative coin issued by the Royal Mint.

Despite courtiers’ efforts to arrange official portraits or media interviews, Anne has refused every suggestion and avoided meetings with royal aides to discuss options.

“She told us she would do things for birthdays that had ‘zeroes, but not for the fives’,” one aide revealed after staff were given strict instructions not to make a fuss.

The £5 silver coin, approved by the princess herself, bears the simple inscription: “The Princess Royal. Celebrating 75 years. Duty and devotion.”

The only other concession Anne made was hosting more than 100 of her charities at a Buckingham Palace reception last month.

Anne’s serious horse accident in June 2024 forced the typically unstoppable royal to confront her mortality and future plans.

The princess was admitted to intensive care with a concussion and head injuries that doctors believed were consistent with being struck by a horse at Gatcombe Park.

“It just reminds you, shows you you never quite know, something (happens) and you might not recover,” Anne reflected in an interview during an official visit to South Africa in January.

“You’re jolly lucky if you can continue to be more or less compos mentis, and last summer I was very close to not being.”

A source who knows Anne well revealed: “Her accident was so much worse than anyone let on, and it took quite a while for her to feel herself again.”

Despite approaching her 75th birthday, Anne remains the hardest-working member of the Royal Family, completing 474 engagements last year compared to the King’s 372.

When asked earlier this year about retirement, she replied: “It isn’t really an option,” hinting at the reduced number of working royals following Prince Harry’s departure and Prince Andrew’s demotion.

The Princess Royal maintains strong relationships with her siblings, particularly King Charles, whom she greeted with “Hello, old bean” in footage from his Coronation preparations.

However, sources close to Anne note her frustration with Prince William’s workload, particularly regarding investitures at Windsor Castle.

“She’s still doing most of the investitures (at Windsor) even though William lives there. It annoys her,” a source revealed, suggesting she would prefer to see her nephew undertake more “bread-and-butter” royal engagements.

Anne will spend her 75th birthday as she does every August, sailing around western Scotland with her husband, Vice Admiral Sir Tim Laurence, for approximately ten days without any staff aboard.

“It speaks to their relationship,” a friend observed. “They go every May and August and have done it for years. How many couples could go out to sea that often, just the two of them, and still be speaking to each other? She loves it.”

Friends describe being at sea with Laurence as her “happy place” and evidence of their strong marriage.

The source close to Anne noted: “She would like to do it while she is still in reasonable health and she can enjoy some time at Gatcombe (Anne’s home in Gloucestershire).

A driving force is also Tim, [Vice Admiral Sir Tim Laurence, Anne’s husband], who is very supportive of her. One of his main concerns has always been that she doesn’t burn herself out.”