Prince William Hails Sir David Attenborough's Century Mark at Royal Albert Hall Concert

Prince William congratulated Sir David Attenborough on reaching a "remarkable milestone" during a concert marking the broadcaster and environmentalist's 100th birthday at London's Royal Albert Hall on Friday.

The event featured memories from Sir David's seven-decade career, live music and special guests. "It is a rare privilege to celebrate a century of life," Prince William said, "but it is rarer still when that person has transformed the way we see the only home that we have - planet Earth."

A cast of animals delivered a card from King Charles at Balmoral Castle in Aberdeenshire to Sir David in London. Birthday messages played on screen from celebrities including Leonardo DiCaprio and Dame Judi Dench.

Host Kirsty Young welcomed guests such as broadcaster Sir Michael Palin, a friend of Sir David's. Musicians included Sigur Rós and Bastille's Dan Smith.

In a pre-recorded video, King Charles wrote his letter, which said he and the Queen sent their "warmest congratulations on such a special occasion." He added that Sir David had "revealed the beauty and wonders of nature to audiences around the world in new and marvellous ways."

"In so doing, you have shared my determination to highlight the urgent need to protect and preserve this precious planet of ours - and all life on Earth - for future generations," the King wrote. "Thank you for all that you have done, and on behalf of the whole nation, I wish you a very happy 100th birthday."

The Queen's dog Moley scampered around the King's feet as he composed the letter and recalled his seven-decade friendship with Sir David. King Charles first met him in 1958 as a nine-year-old visiting the set of BBC children's program Zoo Quest, Sir David's big break as a TV presenter.

The King noted their encounter came "almost a decade before the age of colour television, and of course our paths have crossed many times since."

Viewers saw the letter face obstacles like a fallen tree, but animals including eagles, a hedgehog, a red squirrel and geese carried it across the British Isles to Sir David, who held it up for the audience and received a standing ovation.

In his speech, Prince William told Sir David: "Like millions across the world, my children have grown up with your incredible storytelling - a window into the wonders of nature that shaped their understanding of our planet, and their belief that it is something worth fighting for. And for me personally, your friendship has been profound. You have strengthened my own determination to act."

Prince William added: "Tonight, we celebrate far more than a remarkable milestone of 100 years. We celebrate a lifetime of extraordinary service. A life that has brought the natural world closer to humanity, and humanity closer to its responsibility to the natural world."

Video messages from other celebrities included Dame Judi Dench saying: "Sir David, happy birthday, and how lucky we are to get this opportunity to thank you, for all the things that you've told us and taught us."

Leonardo DiCaprio said: "Thank you truly for everything you've done and continue to do, for our very precious planet and all its inhabitants."

Paddington Bear, Glastonbury chief Emily Eavis, actress Phoebe Waller-Bridge, singer Camila Cabello and composer Hans Zimmer also sent tributes. Actress Olivia Colman said: "Thank you so much for everything you have given all of us throughout the years, the world is a much better place with you in it."

Coldplay frontman Chris Martin said the band "send you so much love and respect," while pop singer Raye said: "Your voice is a gift to this earth, you are a national treasure."

The BBC Concert Orchestra played live throughout, accompanying sequences like the snakes and iguanas chase from Planet Earth II and seals versus orcas from Frozen Planet II.

Dan Smith later joined the orchestra for Bastille's hit Pompeii. Sigur Rós performed their 2005 song Hoppípolla, used in many wildlife programs, films, trailers and ads.

Most performances featured archival footage from Sir David's career. Wildlife presenters Liz Bonnin, Steve Backshall and Chris Packham discussed his influence on policies like reduced plastic straw and bag use after Blue Planet II.

Sir Michael Palin recalled how Sir David commissioned Monty Python as BBC Two controller. He said their friendship grew and Sir David's success came from always "just looks as though he's happy to be there."

As the concert ended, the BBC announced Sir David will narrate Blue Planet III. A montage of his career highlights closed the night, set to his narration of What a Wonderful World.

Kirsty Young told him: "Thank you David, not just for joining us here tonight, but for sharing your knowledge and love of the planet. You've given nature a voice, and what a voice it is."