The royal family is understandably celebrating one of the United Kingdom’s most legendary icons on his birthday. And it’s not just any birthday. Today, Sir David Attenborough turns 99 years old. The renowned wildlife documentarian and conservationist is being celebrated worldwide (he even got a shoutout from the Irwin family matriarch!), and the second in line to the British throne was quick to show his love.

“As he turns 99 today, in his new film, Sir David has once again reminded us of the need to protect natural habitats — this time those beneath the ocean,” Prince William captioned a carousel on Instagram. “He has dedicated his life to ensuring we understand the realities of what mankind is doing to the planet.”

LONDON, UNITED KINGDOM - MAY 13: Catherine, Duchess of Cambridge and Prince Harry as they host a tea party in the grounds of Buckingham Palace to honour the children of those who have died serving in the armed forces on May 13, 2017 in London, England.

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Copyright: Duke and Duchess of Cambridge. NEWS EDITORIAL USE ONLY. NO COMMERCIAL USE. NO MERCHANDISING, ADVERTISING, SOUVENIRS, MEMORABILIA or COLOURABLY SIMILAR. NOT FOR USE AFTER 31 DECEMBER, 2020, WITHOUT PRIOR PERMISSION FROM KENSINGTON PALACE. This photograph is provided to you strictly on condition that you will make no charge for the supply, release or publication of it and that these conditions and restrictions will apply (and that you will pass these on) to any organisation to whom you supply it. There shall be no commercial use whatsoever of the photographs (including by way of example only) any use in merchandising, advertising or any other non-news editorial use. The photographs must not be digitally enhanced, manipulated or modified in any manner or form and must include all of the individuals in the photograph when published. All other requests for use should be directed to the Press Office at Kensington Palace in writing. MANDATORY CREDIT: Kensington Palace. The Duke and Duchess of Cambridge, Prince George (seated), Princess Charlotte and Prince Louis with Sir David Attenborough in the gardens of Kensington Palace in London after The Duke and Sir David attended an outdoor screening of Sir David's upcoming feature film. (Photo by Kensington Palace/PA Images via Getty Images)

Sir David Attenborough with Prince William, Kate Middleton, and kids George, Louis, and Charlotte at Kensington Palace in Sept. 2020
Kensington Palace/PA Images via Getty Images

The Prince of Wales started the carousel with a candid of him and Attenborough smiling together. He then shared the most precious throwback from Kensington Palace. Prince William and Kate Middleton were in the gardens with Attenborough and their kids, Prince George, Princess Charlotte, and Prince Louis.

The shot was taken in 2020, and the kids — now 11, 10, and 7, respectively — look so stinkin’ cute! They are coordinating in blue outfits. Prince George has a hint of a smile on his face as he plays with the tooth of a giant shark that Attenborough gave him. Charlotte looks just darling in her blue and white dress and matching shoes. Her head rests in her hands as she smiles up at the famed broadcaster. Middleton can’t help but smile down at her daughter (with whom she is twinning, of course!), and Prince Louis is so adorable in his collared sweater, shorts, and tall socks. (Yes, this throwback is from before he was allowed to break royal tradition and make the “suburban” move toward pants.)

“However hard-hitting his message is, Sir David always leaves us with a sense of hope and optimism that all is not lost and this film is no different,” Prince William continued. “We must act together, with urgency, to restore our oceans.”

The Prince of Wales signed off by wishing Attenborough a Happy Birthday, and we have to do the same. Happy Birthday to the man, the myth, the legend himself!

Before you go, check out Prince Louis’ most hilariously chaotic moments.