Prince Louis is all smile as he takes on nursery school in his third birthday portrait.
The little royal's birthday is just two days after that of his great-grandmother, Queen Elizabeth. The queen did not share a new portrait on her birthday this year as she mourns the death of her husband, Prince Philip.
Though it's been a sombre week for the royal family, having buried the Duke of Edinburgh on Saturday, the Duke and Duchess of Cambridge returned to their royal duties by visiting the East Ham Air Cadets and doing work for Prince William's Earth Shot Prize on Earth Day, before sharing their youngest son's birthday portrait.
"Three tomorrow!" the Cambridge's captioned Prince Louis' photo on Thursday. The image was taken by mom, Kate Middleton, earlier this week.
SEE AN ADORABLE LOUIS BIKING TO SCHOOL HERE: