The Queen thanked the nation for a series of heart-warming Diamond Jubilee celebrations marking her 60 years on the throne.
In a televised address, she said it had been a "humbling experience".
But missing from her side today was the Duke of Edinburgh, who she famously described as her "strength and stay" on her golden wedding anniversary in 1997.
The Queen waved to the crowds of 1.5m on the palace balcony
His absence is likely to have given the day a bitter-sweet taste for the monarch, who relies heavily on her consort.
After visiting him in hospital, their youngest son the Earl of Wessex said Philip, 90, who is suffering from a bladder infection, was "getting better" and was watching events on TV.
The Queen thanked Britons after four days of jubilee celebrations
The Queen set the seal on a weekend of celebrations by making a Buckingham Palace appearance with close members of her family in front of what organisers estimated was a crowd of more than a million.
Smiling and looking visibly moved by the reaction, she was surrounded by the Prince of Wales, Duchess of Cornwall, Duke and Duchess of Cambridge and Prince Harry as they watched a fly-past of Second World War aircraft and the Red Arrows.
Crowds have been a major feature of the four-day Bank Holiday with huge numbers turning out for all the key royal events - River Thames Pageant, concert and carriage procession.
The Duke and Duchess of Cambridge and Prince Harry travelled behind in another state landau
In her message the Queen said: "The events that I have attended to mark my Diamond Jubilee have been a humbling experience.
"It has touched me deeply to see so many thousands of families, neighbours and friends celebrating together in such a happy atmosphere."
She added: "I hope that memories of all this year's happy events will brighten our lives for many years to come.
"I will continue to treasure and draw inspiration from the countless kindnesses shown to me in this country and throughout the Commonwealth. Thank you all."
Tributes have been paid to the Queen throughout the weekend with the Archbishop of Canterbury, Dr Rowan Williams, praising the Queen's dedication to country and Commonwealth in a St Paul's Cathedral thanksgiving service today.
Charles gave a moving speech on the stage of last night's Diamond Jubilee concert, calling the Queen "Mummy" and describing her as "a very special person".
American President Barack Obama, who has developed a strong bond with the Queen, said she was a living witness to the power of the alliance between the UK and US.
In a video message, he said: "We have stood tall and strong and faced some of the greatest challenges this world has known.
"While many presidents and prime ministers have come and gone, your majesty's reign has endured."
Barack Obama's video message
Prime minister David Cameron said street parties across the UK showed the nation pulling together, while the Olympics would be a "giant advertisement" for the country across the globe.
The Diamond Jubilee weekend has been four days of contrasts for the Queen, encompassing spectacular sporting, musical, and cultural events.
The Queen started her celebrations at the Epsom Derby on Saturday surrounded by the racing world of thoroughbreds, jockeys, trainers and owners.
More than a million people attended the Pageant on the River Thames which was hailed a success despite the cold conditions and persistent rain which deluged participants and public.
The flotilla event on Sunday was the last time the Duke was seen but he appeared to be enjoying himself throughout and did not look to be in discomfort.
Stevie Wonder serenaded the Queen at the star-studded music concert staged in the shadow of the palace and Sir Paul McCartney brought the house down playing a string of Beatles hits.
But just a few hours before the concert began yesterday evening it was announced Philip had been taken to hospital.
Today saw more formal engagements for the Queen, from a City of London Livery Companies lunch in Westminster Hall to a reception for the thanksgiving service congregation.
Take a look at pictures from Tuesday's Diamond Jubilee celebrations below:
Diamond Jubilee Celebrations
SEE ALSO
- Thanksgiving Service At St Paul's Cathedral Begins With A Fanfare
- Queen Greets Cheering Crowds As Flypast Ends Diamond Jubilee Celebrations
- Kate Stuns In 'Nude' McQueen Dress
- Rowan Williams Praises The 'Huge Risk' Of Queen's Lifelong Dedication At St Paul's
- Gary Barlow, Cheryl Cole, Robbie Williams, Kylie Minogue, Paul McCartney Sing For Her Majesty (PHOTOS)
- HM Queen Moved By Duke Of Edinburgh's Absence, and Prince Of Wales's Emotional Tribute
- Kate, Duchess Of Cambridge, Stuns In 'Nude' Alexander McQueen Lace Dress
- Labour MP Lambasts Jubilee 'Slave Labour'