Prince Louis Smiles in Precious First Day of Nursery School Pic Ahead of His 3rd Birthday

The toddler started his first day of nursery school on Wednesday.

Prince Louis is turning 3! Prince William and Kate Middleton's third child turns 3 years old on Friday, and the family celebrated by releasing an adorable new pic of the toddler. 

Per tradition, the photo was taken by Louis' mom, Kate. This year's snapshot shows Louis at Kensington Palace shortly before the little one left for his first day of nursery at the Willcocks Nursery School on Wednesday.

Louis proudly sports his backpack in the photo, and appears ready to go on his little red bike. 

Fans have seen Louis' playful personality blossom over the years. He was all smiles in his first set of portraits, released before his first birthday. 

And ahead of his second birthday, the family shared precious photos of Louis getting colorful with some paint at Anmer Hall, in Norfolk, England, where they were quarantined last spring. 

Louis' smile also brightened up his family's Christmas card, where he posed alongside sister Princess Charlotte, 5, and brother Prince George, 7. 

Louis' birthday comes just two days after his great-grandmother, Queen Elizabeth II, turned 95. The queen spent her milestone birthday at Windsor Castle, as she continues to mourn the death of her husband, Prince Philip. 

It was at Philip's funeral that Kate played "peacemaker" between her husband, Prince William, and his brother, Prince Harry. See more in the video below.