Prince Louis has had a busy year, from his red carpet debut to his first speaking appearance

Happy third birthday — and first day of preschool — Prince Louis!

Kate Middleton and Prince William's youngest child turns 3 on Friday, and the proud parents marked the occasion a day early by releasing a new photo of the little prince before he left for his first day of preschool.

"The Duke and Duchess of Cambridge are delighted to share a new photograph ahead of Prince Louis' third birthday tomorrow," Kensington Palace said in a statement on Thursday.

Louis is all smiles as he sports a backpack and poses on his red bike in the sweet snap, which was taken by Kate Middleton outside the family's Kensington Palace home on Wednesday. The young prince is attending London's Willcocks Nursery School, the same school big sister Princess Charlotte attended.

A royal source told PEOPLE at the time, "They chose that nursery because they thought it would be an ideal first step for Charlotte's education, and they were impressed by the team who work there."

The nursery school is the perfect choice for Louis given that siblings Prince George and Princess Charlotte both attend Thomas's Battersea nearby.

Prince George and Princess Charlotte on their first days of nursery school
| Credit: Duchess of Cambridge/PA Wire/Getty; The Duchess of Cambridge/KENSINGTON PALACE/HANDOUT/EPA-EFE/Shutterstock

Kate also previously shared photos of George and Charlotte on their first days of nursery school. Charlotte started Willcocks Nursery School in January 2018, while George headed to preschool at the Westacre Montessori School in Norfolk in January 2016. Louis' later start date was likely affected by the latest lockdown in the U.K. amid the ongoing COVID-19 pandemic.

To celebrate his second birthday last year, Kate and William shared photos of Prince Louis taking part in a special at-home arts and crafts project: rainbow-colored finger paintings in support of National Health Service (NHS) workers and other essential workers tackling the coronavirus pandemic across the country.

The adorable photos — in which Louis kept his clothes impeccably clean despite smearing paint all over his face — were taken by Kate.

Even at his young age, Prince Louis has been preparing for royal life more than ever in the past year.

In March 2020, he starred in an Instagram video alongside big brother Prince George, 7, and big sister Princess Charlotte, 5, participating in the Clap for Carers movement amid the coronavirus pandemic.

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Prince Louis made his first public speaking appearance alongside his older siblings in October, asking his very own animal questions to Sir David Attenborough in a video shared on social media. Louis adorably asked the famed naturalist, "What animal do you like?"

The Cambridge kids also made their red carpet debut in December during a night out at the theater.

Kate Middleton, Prince William, family
Kate Middleton, Prince William, Prince Louis, Princess Charlotte and Prince George
| Credit: Max Mumby/Indigo/Getty

The entire royal family is mourning the loss of Prince Philip, who died on April 9 at age 99. Ahead of the Duke of Edinburgh's funeral last weekend, the royal family shared never-before-seen photos of Prince Philip with his great-grandchildren, including a 2018 shot taken by Kate where a baby Louis sits on Queen Elizabeth's lap.

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Prince William honored his beloved grandfather with a moving tribute, including how thankful he was for Prince Philip to spend years with his wife and children.

"I will always be grateful that my wife had so many years to get to know my grandfather and for the kindness he showed her," William, 38, wrote. "I will never take for granted the special memories my children will always have of their great-grandpa coming to collect them in his carriage and seeing for themselves his infectious sense of adventure as well as his mischievous sense of humour!"