Kate Middleton and Prince William joined the royal family in wishing Princess Anne a happy 75th birthday on Friday.

On their social media pages, the Prince and Princess of Wales shared Anne’s new royal portrait, with a sweet message: “Wishing Her Royal Highness The Princess Royal a very Happy 75th Birthday!”

Buckingham Palace released the new picture of the Princess Royal this week ahead of her milestone birthday. The photograph was captured by John Swannell last month at Gatcombe Park, Princess Anne’s private residence and equestrian estate in Gloucestershire.

Swannell is well known by the royal family and the Princess Royal in particular. He previously took Anne’s picture for her 40th birthday in 1990, 50th birthday in 2000, 60th birthday in 2010 and her 70th birthday in 2020.

He was also personally commissioned by Princess Diana in 1994 to photograph her with her sons, Prince William and Prince Harry.

While rumors surfaced in the Sunday Times last month that Princess Anne has been “annoyed” with William for not taking on more royal duties, such as investitures, the outlet also reported that the Princess Royal is “fond of her nephew” and plans to support him as he moves closer to the crown.

For his part, Prince William, 43, “is known to admire his aunt’s devotion to duty,” the outlet reported.

“Even if there is any annoyance, there’s mutual respect as well as affection between Princess Anne and Prince William as all who know them can confirm,” British royals expert Hilary Fordwich told Fox News Digital.

“Princess Anne remains most supportive of Prince William’s future as king,” she said. “She admires his sense of duty and commitment to the crown as well as his being a good family man rather than so many of his Prince of Wales predecessors who have, throughout history, been notorious for their womanizing while awaiting ascending to the throne.”

“As Prince William grows into his role, we are likely to see more collaboration for future royal events, particularly at Windsor,” Fordwich continued. “There is a balance to bear in mind between Prince William’s current greater focus on his family versus the more traditional ceremonial approach Princess Anne has upheld. He is well aware of this.”

Princess Anne has long been considered the “hardest-working royal,” and the Buckingham Palace social media account paid tribute to her dedication to the crown in their own birthday post.

“Known for having one of the busiest working schedules of any member of the Royal Family, The Princess has established significant and ongoing relationships with numerous charities and organizations across the Commonwealth,” one slide said, over a throwback photo of Princess Anne in uniform and holding the reins of a horse.

The post also celebrated the second child and only daughter of the late Queen Elizabeth and Prince Philip with insight into her Princess Royal title, a new tiara portrait with her husband, Vice Admiral Sir Timothy Laurence, and a childhood picture of her kids, Peter Phillips and Zara Tindall.

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Princess Anne’s birthday comes as members of the royal family are preparing to spend the late summer together at Balmoral Castle in Scotland.

On Monday, Aug. 11, the royal residence’s official Instagram account announced that they were closing the grounds to the public for the summer, hinting that the royal family’s stay there was starting soon.

Balmoral has been the royal family’s summer escape since the reign of Queen Victoria. The castle and its grounds were a favorite of the late Queen Elizabeth, who was known to leave for Scotland in late July until October.