The Queen has said she remains “committed to serving” the nation to “the best of my ability”, after she set the seal on her Platinum Jubilee celebrations by appearing on the balcony of Buckingham Palace.

The 96-year-old monarch was absent for much of the extended Bank Holiday weekend, after finding the first day enjoyable but tiring, and in a message of thanks acknowledged this but said her “heart” had been with well-wishers.

The Duchess of Cornwall, patron of the Big Lunch, estimated that up to 18 million people could have taken part in Jubilee street parties, and the Queen expressed her hope this “renewed sense of togetherness” would be felt for years to come.

After the outpouring of public affection during her balcony appearance, the Queen said she was “humbled and deeply touched” so many people had taken part in celebrations marking her 70-year reign.

Surrounded by her family, she was cheered by thousands of well-wishers after stepping on to the balcony following the Platinum Pageant, which told the story of her life, and the nation, with an eccentric, fun and imaginative carnival-like display.

Smiling as she acknowledged the spectators, she looked down on The Mall where tens of thousands had waited in hope of seeing her.

The Queen said later in her message: “When it comes to how to mark seventy years as your Queen, there is no guidebook to follow. It really is a first. But I have been humbled and deeply touched that so many people have taken to the streets to celebrate my Platinum Jubilee.

“While I may not have attended every event in person, my heart has been with you all; and I remain committed to serving you to the best of my ability, supported by my family.

“I have been inspired by the kindness, joy and kinship that has been so evident in recent days, and I hope this renewed sense of togetherness will be felt for many years to come.

“I thank you most sincerely for your good wishes and for the part you have all played in these happy celebrations.”

The Queen had not been seen since she made two balcony appearances on the first day of the Jubilee celebrations, when Trooping the Colour was held, and the Duchess of Cambridge later said she had found the day enjoyable but tiring.

But the Queen looked at ease on the balcony as the celebrations drew to a close, leaning on a walking stick, now a routine aid following her mobility issues, and acknowledging the crowds with a wave.

The Prince of Wales stood with the Queen along with the Duchess of Cornwall, Duke and Duchess of Cambridge and their children Prince George, Princess Charlotte and Prince Louis.

After the national anthem was sung by a choir of celebrities including Sir David Jason, Harry Redknapp, Sir Cliff Richard, Sandie Shaw and Felicity Kendal, the Queen waved again at well-wishers and was joined by her great-grandchildren, with Louis waving with both hands.

The royal family had planned to see a display by the Red Arrows from their balcony vantage point, but it was called off due to the low clouds which had threatened rain all day.

Earlier in the day Charles had expressed the same sentiment as the Queen when he spoke about the camaraderie the Jubilee events had fostered.

He told revellers at The Big Lunch’s flagship event in London, which he attended with Camilla, that he hoped “bickering” did not return after the feeling of “togetherness” across the nation.