The youngest prince of William and Kate celebrates his 4th birthday today and as a sign to remember the special date, the couple as rarely posted a photo of the little one.

The little prince that the world still remembered with the portrait of the little one, appears laughing on the beach, in Norfolk, England.

"4 years old tomorrow." - it is written in the published post.

Louis was born on April 23, 2018, after Prince George and Princess Charlotte. Its title is "Royal Highness Prince Louis of Cambridge", while it is currently the fifth line for the royal throne, after grandfather, father, brother and older sister.