Royals British Royal Family Prince Charles' 'Future Role as King' Was 'Visible' During Platinum Jubilee, Says Royal Historian Queen Elizabeth limited herself to just a few appearances over the four days of festivities due to her ongoing mobility issues By Simon Perry Simon Perry Simon Perry is a writer and correspondent at PEOPLE. He has more than 25 years’ experience at PEOPLE covering the royals, human interest and celebrity. People Editorial Guidelines Published on June 9, 2022 01:51PM EDT Prince Charles and Queen Elizabeth in June 2022. Photo: Hannah McKay/getty Queen Elizabeth's Platinum Jubilee celebrations doubled as a preview of the future of the monarchy in the hands of Prince Charles. The Queen, 96, limited herself to just a few appearances over the four days of festivities due to her ongoing mobility issues and "discomfort," meaning her heir and son Prince Charles took the lead at multiple events. From taking the salute on horseback at Trooping the Colour to leading the tributes at the Platinum Party at the Palace, Charles was in the spotlight. "[The Queen] sees this as a great opportunity for the transition to be visible," royal historian Robert Lacey tells PEOPLE in this week's issue. Adds Sally Bedell Smith, author of Elizabeth the Queen: The Life of a Modern Monarch: "She is in the saddle, but this gets people accustomed to [Charles's] future role as King. There was a feeling of celebrating the past and anticipating the new era." Inside Queen Elizabeth's Decision to Step Back from Jubilee Events: 'She Would Not Want to Stumble' Prince Charles and Prince William. Samir Hussein/WireImage Prince William also played a central role in the celebrations alongside his wife Kate Middleton and their three children, taking on a visit to Wales and appearing with his father and grandmother on the Buckingham Palace balcony during Sunday's Platinum Jubilee Pageant finale. Chris Jackson/Getty The Platinum Jubilee was also an opportunity for the royal family's relationships to be displayed, like when 4-year-old Prince Louis took a seat on grandfather Prince Charles' lap during the Platinum Jubilee Pageant. "How utterly charming that was," says a palace insider. "When you consider that he has been said to be a remote parent, to see him do that was charming." Prince Charles and Prince Louis at the Platinum Jubilee. Chris Jackson - WPA Pool/Getty 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! The source adds that although it is often said that Kate's parents, Carole and Michael Middleton, are the grandparents they are close to (and they certainly spent a lot of time with them), "it was lovely to see his other grandfather enjoying time with him too."