ET is looking back at some of the most beautiful moments between the young princes and their mom.
Princess Diana held on tight to her newborn son as she and husband Charles left the hospital on June 22, 1982, just one day after William's birth.
Too cute! William loved being held up high in his mom's arms during a relaxing day at Kensington Palace in February 1983.
Hear Me Out!
Prince William captured his parents' attention as they spent time in a Kensington Palace garden in December 1983.
Fit the Pieces
Diana helped William put together a puzzle in his playroom at their Kensington Palace home.
Diana sat on the front stoop at the family's home, Highgrove House, while Harry played around dressed as a solider in a camouflage uniform on July 18, 1986.
Prince William was clearly excited to show his mom his riding skills while visiting Balmoral, Scotland, with the whole family.
Princess Di accompanied her adorable tots as they tickled the ivories.
Holiday in Spain
The young princes hung out with their mom on the steps of the Marivent Palace when they visited Majorca, Spain, in August 1987.
Majorca With Mom
While on vacation in Majorca, Spain, in August 1987, Harry and his mom spent quality time together while hanging out in the city.
Ribbit! Princess Di and Harry looked for frogs along the banks of the River Dee during their summer vacation in Balmoral that same month.
Harry Gets Goofy
Princess Diana didn't expect son Harry to stick his tongue out while the royal family celebrated Trooping the Colour in July 1988, but it made for a very cute moment!
Diana and William went bike riding together around Tresco during their June 1989 holiday in the Isles of Scilly.
Hanging With Mom
Prince William and his mom kept an eye on the matches during Cartier International Polo Day in Windsor, England, in July 1989.
Diana looked incredibly proud of her dapper boys as they headed out the door on Harry's first day at Wetherby School in September 1989.
Princes Harry and William stayed close to their mom during a day of sun and sand on Necker Island in the Caribbean in April 1990.
Princess Di and her boys hit the slopes of Lech, Austria, in April 1991.
The trio took in the view of Niagara Falls from aboard the Maid of the Mist during a trip to Canada in October 1991.
Princess Di and Harry we're all smiles as they enjoyed the exciting Depth Charge ride at Thorpe Park in Surry, England, on April 18, 1992.
A little water didn't get the grinning trio down when testing out the rides at Thorpe Park in Surrey, England, in 1993.
Your Carriage Awaits
Diana and her boys enjoyed a horse-drawn sleigh ride while vacationing in Austria in March 1994.
The Princess of Wales sat alongside her dapper son Harry during the V-E Day 50th Anniversary Celebrations in Hyde Park, London, on May 7, 1995.
White & Blue
Princess Diana and her son Harry looked absolutely regal while attending the V-J Day 50 Anniversary Celebrations in London on Aug. 19, 1995.
Harry's got something to say! Diana leaned into her boys' conversation during a VJ Day 50th Anniversary commemoration in August 1995.
Diana and Harry both accompanied William to his first day at Eton College in September 1995.