Prince William resumes royal duties after avoiding Prince Harry at uncle's memorial.

The beard is back.

After spending a peaceful summer with Kate Middleton and their three children, Prince William resumed his royal duties with a fresh appearance.

On Thursday, the Prince of Wales visited the "Homelessness: Reframed" exhibit at the Saatchi Gallery in London, which was created in collaboration with the Eleven Eleven Foundation and the royal's Homewards campaign aimed at ending homelessness in the U.K.

On Aug. 11, the 42-year-old father of three, who is known to be clean-shaven, surprised everyone by sporting a beard for the first time in eight years. The occasion was the celebration of Team Great Britain's success at the 2024 Paris Olympics, and the father and his wife were among the attendees.

On Aug. 25, the heir to the British throne was seen driving near Balmoral Castle in Scotland without facial hair.

The royal family, including the Prince and Princess of Wales, their children, and the late Queen Elizabeth II, spent their summer break at her Scottish estate from late July to August.

Middleton, 42, is continuing her cancer treatment.

In 2008, William sported a beard for a Christmas church outing, but he typically remains clean-shaven due to his time in the Royal Air Force, where facial hair is forbidden. In contrast, his younger brother, Prince Harry, has consistently worn a beard for years, first growing it out in 2013.

In his memoir "Spare," Harry asserted that his beard led to tension with William.

Harry remembered requesting permission from Queen Elizabeth to keep his scruff for his 2018 wedding to Meghan Markle. He stated that it was a significant request as beards were prohibited in the British Army, and he would be wearing his armed forces uniform on the big day. The Duke of Sussex explained that his facial hair served as a "security blanket" and that his wife-to-be had never seen him without one.

WATCH: PRINCE WILLIAM ADAMANT ABOUT GIVING HIS CHILDREN A NORMAL LIFE: AUTHOR

The 39-year-old confessed that he didn't want the stranger to be seen by the woman walking down the aisle.

Harry wrote that when he asked William why he was bothered by their grandmother's permission, William replied, "Because I wasn't allowed to keep my beard."

"Harry wrote, "Ah — there it was. After returning from a Special Forces assignment, Willy had a full beard, and someone told him to shave it. He resented the idea of me enjoying a perk he'd been denied.""

King Charles and his grandfather, Prince Philip, were known to experiment with facial hair but generally preferred to keep a clean-shaven appearance.

In August, at a memorial for his late uncle, Lord Robert Fellowes, in the U.K., it is uncertain whether William had a beard.

"He hated the idea of me enjoying a perk he'd been denied." — Prince Harry, "Spare"

Lady Jane Fellowes, Princess Diana's sister, was married to Fellowes. The service took place two days before the 27th anniversary of Diana's death, on Aug. 31.

According to People magazine, while the brothers were present at the Fellowes funeral service at St. Mary's Church in Snettisham, Norfolk, they sat apart from each other and with different groups of their paternal cousins.

The Associated Press contributed to this report.