Happy birthday to Prince William and Kate Middleton's youngest son, Prince Louis! The toddler turns three on Friday and to mark the occasion, his proud parents released the most adorable photo of him.
MORE: Kate Middleton's sweet birthday tradition for Prince Louis revealed
The image, which was shared on social media, shows Prince George and Princess Charlotte's younger brother on his way to his first day of nursery earlier this week. In the photo, which was taken at Kensington Palace on Wednesday by mum Kate, Louis can be seen smiling broadly at the camera whilst riding a balance bike and carrying his backpack.
WATCH: Camilla reveals the adorable activity she does with George, Charlotte and Louis
Fans rushed to comment on the sweet Instagram post on Kensington Royal's official page and most couldn't believe how much the youngster had grown.
" 3?! He was only born the other day," one wrote, whilst a second remarked: "Oh my he's grown so much! Happy birthday!"
READ: Why Prince George had a different start to his education than Charlotte and Louis
MORE: 16 adorable photos of the royals on their first day at school
A third added: "Our baby is not a baby anymore! Happy birthday."
Others, however, were divided over who he looked like the most, with some saying he was "his mum's twin" and others convinced he is "just like his brother George".
Prince Louis turns three on Friday
Louis is attending the same nursery sister Charlotte went to, Willcocks Nursery School, which charges £3,400 per term for children attending morning school, and £2,250 per term for afternoon sessions. It's a short drive from the Cambridges' London home, Apartment 1A at Kensington Palace.
It is likely Kate was invited into the nursery for her first "stay and play" session with Louis, where the parent gradually spends more time away from their child until they are happy to be apart from their mother or father for the whole day.
Louis' older siblings, Prince George, seven, and Princess Charlotte, five, currently attend Thomas's Battersea school in south west London.