Born on April 23, 2018, Prince Louis is the youngest son of Prince William and Kate. He is fifth in line to the throne – behind his older siblings, his father and Prince Charles.
His brother George will turn nine-years-old in July, while Princess Charlotte turns seven in a few weeks.
Four new pictures of Prince Louis, taken by his mother, have been released to mark his fourth birthday.
The images were snapped earlier this month in Norfolk and show him running on a seemingly deserted beach and smiling broadly on the sand.
The latest snaps of the young royal have left the fans gushing over his cuteness.
A twitter user, Sabirah Lohn, tweeted: “Sorry I can’t wait anymore. Prince Louis is too adorable! Happy almost 4th birthday to him! Thank you to everyone that shared this picture.”
A second user, Sharon, tweeted: “Happy Birthday to Prince Louis…He’s growing into a handsome wee man.”
A third user, Stormy seas, tweeted: “Sweet, Adorable, Handsome Prince Louis has such a beautiful smile! Happy Birthday!”
His mother Catherine’s photos have regularly been used to mark her children’s birthdays.
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The 40-year-old is patron of the Royal Photographic Society, and also released a pandemic photography book, Hold Still, in partnership with the National Portrait Gallery last year.
Hold Still featured 100 photographs taken by members of the public during the pandemic, and the Duchess said it would serve as a “lasting record of what we were all experiencing”.
Another twitter user, LeaM, tweeted: “Gorgeous. Catherine is able to catch the personality of her children with her pictures. You can tell he is a wild one. Happy birthday.”
A fifth twitter user, Stephanie Baga, tweeted: “So cutie…. I can’t decide whether he looks like William or Catherine. The boss baby is becoming a real boss kid.”
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Another one, Burkean mama, tweeted: “Oh my gosh, our boss baby is not a baby anymore, what a great smile.”
Another user, Jehny Tolios, tweeted: “Oh my God…Boss Baby has grown up so much! Totes adorable little man. Looks so much like Catherine’s father..”