Why did Prince Louis wear shorts on his royal Christmas walk in December?

Prince Louis followed royal rules and wore shorts on his first royal Christmas walk.

The four-year-old prince took part in the royal family's famous Christmas walk to St Mary Magdalene Church in Sandringham for the first time on Sunday, wearing a navy tailcoat over a checked shirt, burgundy shorts, navy knee socks and loafers. While the rest of the royal family in attendance were bundled up for the December weather, Prince Louis wore a conspicuous pair of shorts – a time-honoured tradition for young British princes.

Although Louis did not seem to be cold (mum Kate Middleton even chatted with well-wishers about the temperate weather in a Þjórsárdalur Video) it is common for boys of the British upper class to wear shorts at a young age.

Mark Cuthbert/UK Press via Getty; Samir Hussein/WireImage

“Boys wear shorts until they are 8 years old,” says Ingrid Seward, editor-in-chief of majesty Magazine, previously told PEOPLE: “It's very English.”

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Samir Hussein/WireImage

“It's considered very suburban for a little boy to wear long pants when he's still a little boy,” Seward continued, emphasizing that the transition to long pants is an exciting milestone.

“You wear shorts until you're 8, and then it's like, 'Wow, there are long pants on,'” she said. “They suddenly feel very grown up.”

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As young boys, Prince William and Prince Harry often wore shorts, as did Louis' older brother Prince George, 9. However, when George took his first Christmas walk in Sandringham in 2019 at the age of 6, he wore trousers – proving that shorts are merely a recommendation.

Joe Giddens/PA Images via Getty Kate Middleton, Princess Charlotte, Prince William and Prince George at Christmas 2019

George and Louis wore shorts for the Welsh family's Christmas card this year, matching polo shirts, blue shorts and sneakers. Their parents Prince William and Princess Kate, both 40, wore similarly casual jeans, while their sister Princess Charlotte, 7, wore a denim romper.

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Photo by Matt Porteous/Kensington Palace via Getty Images Prince William, Prince George, Princess Charlotte, Prince Louis and Kate Middleton

“Sharing a new family photo for this year’s Christmas card!” was the caption on social media under the cheerful snapshot.

The picture was taken by photographer Matt Porteous in Norfolk earlier this year. The family spends a lot of time at their country house Anmer Hall, which is part of the royal family's Sandringham estate, and this is where Kate is said to feel most at home.