The Queen "struggled to not be overcome by tears" as she stood on the Buckingham Palace balcony to mark the final day of her Platinum Jubilee celebrations, according to a body language expert.
Judi James said the monarch narrowed her eyes and sucked in her lips, indicating she was "using all her willpower to avoid breaking down" in public for the first time in her life.
As tens of thousands of people packed on to The Mall, the Queen stepped out on to the balcony on Sunday evening following the Platinum Pageant, which told the story of her life, and the nation, with an eccentric, fun and imaginative carnival-like display.
She was flanked by her three heirs - son, grandson and great-grandson - offering a glimpse into the monarchy's future.
Ms James told the MailOnline : "Forget some of the rare occasions when the Queen has been judged to be crying in the past, they have often involved nothing more than moist eyes which can be prompted by the cold weather or even age.
"This balcony appearance produced more congruent signs that she might have been struggling not to be overcome by tears.
"Her eyes narrowed, with a lifting of the under-eye and she sucked her lips in to suggest she was using all her will power to avoid breaking down in public for the first time in her life."
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 marking her 70-year reign.
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.
The monarch said 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.
