King Charles III remembers Prince Harry during Father's Day

King Charles III took a trip down memory lane to celebrate Father's Day on Sunday, June 18. He shared a photo of himself with his children Prince Harry and Prince William.

The new monarch, through the royal family's Instagram page, shared a series of photos to celebrate fathers everywhere along with the caption, "To Dads everywhere, we wish you a special Father's Day today."

One picture is a throwback photo taken during the family's vacation to Balmoral. It showed a very young Prince Harry, and Prince William was still in his teens.

King Charles III wore a traditional Scottish outfit consisting of a bright green knit sweater and a green checked kilt. Meanwhile, Prince William and Prince Harry went for khaki pants and buttoned-down shirts with the sleeves rolled up. They all appeared to be looking towards something the Duke of Sussex is pointing at out of the camera shot.

According to Page Six, the photo is very poignant because it was taken on Aug. 16. 1997 while the family was on holiday at Balmoral Castle in Scotland. It was two weeks before the brothers were due to reunite with their mother Princess Diana on Aug. 31. Unfortunately, she died on the same day from a tragic car crash in Paris alongside her boyfriend Dodi Fayed while they were being pursued by paparazzi.

Aside from a photo of King Charles III with his sons, the royal family also shared a throwback snap of Queen Camilla with her late father, Bruce Shand. The post also included a photo of His Majesty with his father, the late Prince Philip. Meanwhile, Prince William celebrated Father's Day with a new photo showing him surrounded by all his three children, Princes George and Louis, and Princess Charlotte.

The symbolic throwback picture of the monarch and his children comes amid a tense relationship between him and his youngest son. Prince Harry revealed in a promotional interview for his memoir "Spare" in January that he is no longer on speaking terms with his father and with Prince William.

In his book, the Duke of Sussex also called his own father "cruel" and his brother his "enemy." The 38-year-old wrote that his father was often emotionally distant especially when he broke the news about Princess Diana's tragic death and noted that he did not embrace him to console him.

The BetterUP CIO also revealed in "Spare" that his father would tell "sadistic" jokes about not being his real father, referencing rumours that James Hewitt is his biological dad. But since the memoir's publication on Jan. 10, King Charles III and Prince William have kept to the royal decree of "never complain, never explain" and instead carried on with their public duties.

They have also kept their distance from Prince Harry even when the latter returned to the U.K. in March to attend the preliminary hearing of his privacy suit against Mirror Group Newspapers. The last time he reunited with the British royals was during King Charles III's coronation on May 6 in London's Westminster Abbey. But it is unclear if he met with his father or brother privately ahead of the ceremony. He also did not stay behind after the ceremony and flew back home to his family in California right away.

In the wake of the book's release, His Majesty also evicted Prince Harry and Meghan Markle from Frogmore Cottage, their home in London on the grounds of Windsor Castle. He did not greet his grandson Prince Archie on his fourth birthday on May 6, and also did not wish his granddaughter Princess Lilibet Diana a happy second birthday on June 4. King Charles III reportedly also did not invite the couple to his first Trooping the Colour parade as the new monarch on June 17.