Royals Prince William Jokes About the Queen's Age in Heartwarming Speech at Platinum Jubilee Concert "No one's grandmother thanks them for talking about their age," William said during the Platinum Party at the Palace concert By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Editor, Writer and Reporter at PEOPLE. People Editorial Guidelines and Simon Perry Published on June 4, 2022 05:01 PM Share Tweet Pin Email Prince William and Prince Charles each took the stage separately at Saturday's Platinum Party at the Palace to celebrate the work Queen Elizabeth has done to save the natural world...and how long she's been doing it! William was joined by his wife Kate Middleton and their eldest children Princess Charlotte and Prince George at the star-studded concert. Earlier in the day, the family visited Wales in celebration of the Jubilee weekend. The Duke of Cambridge appeared during the Our Green Planet segment of the show, which opened with pre-recorded words from Sir David Attenborough and spectacular imagery of the planet. William took the stage, opening by stating, "Good evening everyone. It's so wonderful to be here with you on this incredible night. And great to see Buckingham Palace turned into an IMAX screen!" Prince George and Prince William. Chris Jackson - WPA Pool/Getty After noting how "proud" he was of his father Prince Charles and late grandfather Prince Philip for their conservation work spanning decades, he turned his attention to his grandmother. Queen Elizabeth Reveals What's in Her Famous Handbag in Surprise Tea Time with Paddington Bear Skit Kate Middleton, Princess Charlotte, Prince George and Prince William at "Party at the Palace". Jacob King/PA Images via Getty "While no one's grandmother thanks them for talking about their age, my own grandmother has been alive for nearly a century," he said. "In that time, mankind has benefited from unimaginable technological developments and scientific breakthroughs. And although those breakthroughs have increased our awareness of the impact humans have on our world, our planet has become more fragile. Today, in 2022 — as The Queen celebrates her Platinum Jubilee — the pressing need to protect and restore our planet has never been more urgent." For more on the Queen's Platinum Jubilee, listen below to our daily podcast PEOPLE Every Day. He then added a shared quality between them: "But like her, I am an optimist." Prince William said it was his "firm hope that my grandmother's words are as true in seventy years' time as they are tonight that as nations we come together in common cause because then there is always room for hope." Steve Parsons/PA Images via Getty He added, "Tonight has been full of such optimism and joy – and there is hope. Together, if we harness the very best of humankind, and restore our planet, we will protect it for our children, for our grandchildren and for future generations to come." Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! As he concluded his speech, Kate, George and Charlotte waved their Union Jack flags enthusiastically and the children joined in the crowd's applause. Prince Charles was joined by his wife Camilla, Duchess of Cornwall when he took the stage to deliver his speech. Prince Charles. Jonathan Buckmaster/AP/Shutterstock "Your Majesty, Mummy," he began. "The scale of this evening's celebration – and the outpouring of warmth and affection over this whole Jubilee weekend – is our way of saying thank you – thank you from your family, the country, the Commonwealth, in fact the whole world." "Your family now spans four generations. You are our Head of State. And you are also our mother. Your 'strength and stay' is much missed this evening but I am sure he is here in spirit…My Papa would have enjoyed the show and joined us wholeheartedly in celebrating all you continue to do for your country and your people," he continued, praising his late father and the Queen's beloved husband Prince Philip, who died last year at the age of 99. "I know what really gets my mother up in the morning," Charles said. "All of you, ladies and gentlemen." He then told the crowd that if they cheered loud enough, the Queen would hear them from Windsor Castle, which was just 20 miles away.