Prince Louis, the youngest child of Prince William and Kate, the Princess of Wales, and younger sibling of Prince George and Princess Charlotte, is 6.

The Wales family marked the young prince’s birthday by sharing a new photo, taken by Kate.

The photo, shared on William and Kate’s social media accounts, shows a smiling Louis, dressed in a plaid collared shirt, posing outside on a blanket.

Six years ago, on April 23, 2018, the prince, whose full name is Prince Louis Arthur Charles of Wales, was born at 11:01 a.m., local time.

The young prince, a grandson of King Charles III, made his first public appearance just seven hours after his birth, when William and Kate brought him outside St. Mary’s Hospital in London.

In the years since, Louis has been known to steal the spotlight at royal events.

In 2022, Louis captured the public’s eye when he animatedly stood next to his great-grandmother, the late Queen Elizabeth II, on the balcony of Buckingham Palace during her Platinum Jubilee.

Later on at the jubilee’s Platinum Pageant, Louis’s display of facial expressions, waving and even at times screaming, prompted William and Kate to caption a video montage of the event, “We all had an incredible time, especially Louis…,” followed by an emoji of watchful eyes.

The next year, in 2023, Louis had his turn in the spotlight again at Charles’ coronation, where he was seen dancing, waving and, at times, yawning.

Just after the coronation, in early May, Louis marked a royal milestone, attending his first royal engagement.

The then-5-year-old was seen trying archery and shoveling alongside Kate as they were joined by William, George and Charlotte in helping to renovate a hut for a scout troop during the Big Help Out, a coronation event meant to encourage people to volunteer in their communities.

Louis’ birthday this year comes at a less celebratory time for the royal family, which has two members battling cancer.

Louis’ mom, Kate, announced in March that she was diagnosed with cancer and is undergoing chemotherapy.

Just one month earlier, in February, Buckingham Palace announced that Charles was diagnosed with cancer and had begun treatment.

The palace has not specified Charles’ type of cancer, the stage of cancer or the type of treatment.

Likewise, Kensington Palace has not shared details on the type of cancer Kate was diagnosed with. She said in a video message that the cancer was discovered in post-operative tests after her planned abdominal surgery in mid-January.

In announcing her cancer, Kate asked for privacy for her family. The palace has said only that Kate will return to public duties once she is medically cleared to do so.

After taking time off during their children’s Easter school holiday, William returned to work on April 18, visiting a food charity in his first royal engagement back since Kate’s announcement.