King Charles III took to social media on Tuesday to mark his sister Princess Anne's 73rd birthday.
In honour of the special occasion, the monarch opted to post two heartwarming photographs on the royal family's official Instagram page.
In the first photo, taken by Chris Jackson, the sibling duo were pictured at Buckingham Palace sharing a laugh in May 2023 during the King and Queen's majestic coronation. Meanwhile, in a separate black-and-white photo, a young Prince Charles can be seen sweetly holding his little sister's hand from the comfort of their matching prams.
In the snapshot, which was taken at Clarence House in 1951, Princess Anne looked so precious in her ruffled bonnet, whilst the King melted hearts with his smart Peter Pan collar coat.
"Wishing Her Royal Highness The Princess Royal a very Happy Birthday today!" Charles affectionately penned in his caption.
Royal fans were quick to flood the comments section with an abundance of celebratory well-wishes.
Gushing over their strong sibling bond, one follower remarked: "Love this so much [red heart emoji] always looking at each other with respect and love," while another wrote: "Amazing set of photos!!! Happy Birthday Anne!!! May you turn maaaaaany more!!"
A third commented: "Happy birthday Princess Anne [balloon emoji] both pictures are lovely," and a fourth sweetly added: "What a lovely picture of His Majesty and Her Royal Highness, thanks for sharing! Happy birthday to The Princess Royal."
Princess Anne Elizabeth Alice Louise was born on 15 August 1950 at Clarence House, as the second child of the Queen and the late Duke of Edinburgh.
She was educated at Benenden School in Kent and left with six GCE O-Levels and two A-Levels. She began to carry out royal engagements in 1969 at the age of 18 and she was the first member of the royal family to compete in the Olympics in Montreal in 1976.
Whilst it's not known how she will celebrate her special day; we imagine she will likely spend it with her relatives.
The Princess Royal shares two children, Peter Phillips and Zara Tindall, with her first husband, Captain Mark Phillips.
She went on to marry Vice Admiral Sir Timothy Laurence at Crathie Kirk near Balmoral Castle on 12 December 1992.
Beyond this, she is a doting grandmother to five children: Mike and Zara's three children Mia, Lena and little Lucas, in addition to Peter and his former wife Autumn's two daughters Savannah and Isla.
A friend of the Princess previously described her as a "fun-loving granny", telling the Daily Mail: "Anne loves to play games with them, the messier the better. Her influence on the little ones is clearly shown in the fact they're country girls who love getting filthy and mucking about."