Royals The Most Adorable Photos of Birthday Boy Prince Louis The youngest child of Prince William and Kate Middleton could not be any cuter! See the young prince grow up through these sweet throwback photos By Diane J. Cho Diane J. Cho Diane J. Cho was the Features Editor of PEOPLE Digital from 2019 to 2022. She worked at the brand for nearly four years covering news, features, human interest, evergreen, holiday gift guides and more. She launched the How I Parent and What It's Really Like to Be …. digital series and has interviewed several celebrities and influential leaders within the entertainment industry. Prior to joining PEOPLE, Diane worked at Bustle, VH1 and Complex. She received her bachelor's degree in Journalism from Rutgers University and her master's degree from Columbia Journalism School. People Editorial Guidelines Published on April 23, 2022 08:00 AM Share Tweet Pin Email Trending Videos 01 of 09 Sleeping Prince Shutterstock Kate Middleton cuddles a sleeping baby Louis as they arrive for his christening service at the Chapel Royal, situated within the grounds of St. James's Palace, in July 2018, three months after his April 23 birthdate. 02 of 09 Baby Brother Prince Louis and Princess Charlotte. HRH Duchess of Cambridge via Getty Newborn Louis gets a kiss from big sister Charlotte on her 3rd birthday at Kensington Palace in London in May 2018. 03 of 09 Sucker for You Max Mumby/Indigo/Getty Siblings George, Louis (adorably sucking his thumb) and Charlotte watch from the window during Trooping the Colour, the Queen's annual birthday parade, in June 2019. 04 of 09 Feeling All the Feels Prince Louis, Prince William, Kate Middleton, Prince George and Princess Charlotte. Samir Hussein/WireImage After gazing from the window, the royal siblings join parents Prince Charles and Kate Middleton to wave to the crowds in person. (From the looks of it, Louis may have wanted to go back inside!) 05 of 09 Smiling Spectators Max Mumby/Indigo/Getty Mom Kate Middleton and Prince Louis watch a flypast from the balcony of Buckingham Palace during Trooping the Colour, and little Louis gives a little wave. 06 of 09 Big Applause Comic Relief/BBC Children in Need/Comic Relief via Getty The royal family applauds NHS carers, as part of the BBC Children in Need and Comic Relief special, in London in April 2020 during the early days of the COVID-19 pandemic. Little Louis gives his best teeny claps, as his mom holds him in her arms. 07 of 09 Keeping Close to Mom AARON CHOWN/POOL/AFP via Getty Prince Louis of Cambridge holds his mom's hand as they attend a special pantomime performance of The National Lottery's Pantoland at London's Palladium Theatre in December 2020. 08 of 09 Happy Christmas! The Cambridge family's 2020 Christmas card. Matt Porteous / The Duke and Duchess of Cambridge/Kensington Palace via Getty The youngest royal is front and center for the family's 2020 Christmas card, shot at Anmer Hall in Norfolk, England by Matt Porteous. 09 of 09 Playful Prince! Prince Louis. KENSINGTON PALACE/AFP via Getty Images Prince Louis frolicks on the beach near his family's home in Norfolk in a series of new photos in celebration of his 4th birthday on April 23.