The day the Queen joked she looked just like Miss Piggy in Gyles Brandreth’s new biography

When she settled into an open carriage for a birthday ride through Windsor, the Queen was in for an unexpected surprise. On the sofa lay a bunch of flowers and next to it a card in an envelope.

At first she smelled the flowers; then she opened the envelope and looked at the card before bursting into laughter.

The card, which was signed by staff at the Royal Mews at Buckingham Palace, where the carriages and horses are kept, depicted the Muppet character Miss Piggy.

“I thought, ‘Well, she can’t fire us all,'” said palace coachman Alfred Oates, who worked for the Queen for 57 years. “But there she was, as the crowd could see, laughing all the way.”

Some of the more dour courtiers of the palace found Oates and his team overbearing, to say the least.

The Queen, however, was in on the joke. Years earlier, she had watched a video of herself and shouted to her husband, ‘Oh Philip, look! I’ve got my Miss Piggy face on.”

As Gyles Brandreth’s sparkling new biography of the late Queen reveals, this instinct and self-deprecation was as important a part of her personality as the clothes she wore and the smile on her face.

And perhaps nothing was more important than her ability not only to take a joke, but to accept a joke.

Time and again she showed that she could see the funny side of everything, no matter how difficult the circumstances.

Take, for example, the infamous Buckingham Palace break-in in 1982, when intruder Michael Fagan climbed a drainpipe and forced his way into the Queen’s bedroom, where she lay in bed.

While the world was agitated by the peril into which the monarch had been placed, the Queen herself was perfecting the reaction of her chambermaid, Lizzie, when she saw Fagan.

For weeks afterwards, the Queen entertained her friends and family by imitating Lizzie’s broad Yorkshire accent. “Damn, ma’am,” she would say. “What’s he doing there…?”

She had long known that humor was an invaluable royal skill, not only during her public duties of putting the overwhelmed and the lost at ease, but also privately.

Once, annoyed by Prince Andrew’s behavior, she sighed to her then daughter-in-law, Sarah Ferguson, “I’m so glad you took Andrew off your hands, but why on earth did you do it?” The laughter that followed the remark hid the shadow that was already falling over the marriage.

The psychology of such comments is, of course, illuminating. So what are we to think of her observation of Andrew – as reported by Brandreth – after he explained the sad saga of his long relationship with sex offender Jeffrey Epstein, which led to him being stripped of his public roles?

“Intriguing,” was her one-word reply. Certainly, it illustrates her mastery of understatement and also her penchant for brevity. The Queen never said more than was absolutely necessary.

Dry and sardonic, yes, but also mysterious. It’s tempting to wonder what Andrew made of it. Did he, as some have suggested, take his mother’s comment as a sign that she had forgiven him, or was he just as perplexed as the rest of us?

For many years, the Queen’s ability to remain silent, speaking volumes, was undoubtedly one of her greatest strengths.

When a minister’s mobile phone rang – in violation of the rules – while attending a Privy Council meeting, she said cuttingly, “I hope that wasn’t someone important.”

With the Queen, duty always went hand in hand with laughter. Many of her friends have testified how often she found things amusing and how they sometimes saw her laugh “until she cried.”

“She had a great sense of the ridiculous,” a companion explained. “You only have to think about what happened when she lost her lipstick in the toilet.

“It was at a private party and she had gone to the ladies” accompanied by a lady-in-waiting. The lipstick rolled under the door of a booth, which was occupied – so they had to wait for the other person to leave before they could pick it up.

“The Queen thought it was all extremely funny and couldn’t help laughing.”

She would find humor in the most unexpected places. Sir Michael Oswald, who was the Queen’s racing adviser, liked to tell the story of a horse she had in training named Harvest Song.

He phoned her page, Barry Mitford, at Buckingham Palace one morning to say it was running at 2.30am at Fontwell and that it was on TV, in case they wanted to watch or record it for her. “Barry got quite excited about this and asked if it was going to win and if he was going to flutter,” Sir Michael recalled. “I told him not to waste any money on it: that I had a better chance of winning the 100 meters at the Olympics.”

Harvest Song started as a 50-1 outsider and won the race by five-and-a-half lengths.

When Sir Michael later telephoned the Queen to ask if she had seen the race, she replied, “Oh yes, and may I say Barry is beside me.” If I were you I’d get some dark glasses and a good disguise next time you come around here.”

So where did this sense of humor come from and how important was it to the Queen?

Some of it is undoubtedly inherited. The Queen Mother can be mischievous. “Did you reign today, Lilibet?” she asked her daughter in mock seriousness as the Queen returned from an engagement.

Her joke when she learned at the age of 95 that a masked intruder with a crossbow — intercepted in the grounds of Windsor Castle — had announced that he had come to kill the Queen, could have come from her wagging mother. “Well, that would have put a damper on Christmas, wouldn’t it?”

But at the same time, the Queen’s exposure to the male-dominated royal world, where wasps aside and relentless disdain are part of the currency of palace life, was also crucial.

“It’s fast, sardonic and it’s observed,” says a palace figure. “And the queen loved it.”

Irreverent impressions were her forte. Aides recall the time a North Country mayor was introduced to the Queen and insisted on complimenting her by saying how much prettier she was in real life than in her photographs.

“Later that day, the Queen made an impression of the poor man telling her this in a Northern accent that made everyone hold their side, including Prince Philip,” says the retired courtier.

“She wasn’t mocking him, she was just having fun.”

Michael Noakes, the eminent artist, was at Buckingham Palace painting her for the City of Manchester in her Order of the Bath robes, and for the best light effect had her standing by a window in the Yellow Drawing Room.

As he later told me, “She was peering out the window and keeping a running commentary of people’s reactions when they saw her standing there – ‘Gosh, Maud [in an American accent] it’s not possible’. . . “Oh no, he’s decided it can’t be done, he’s moved on now.” And: ‘Ooh, a car just got hit by a taxi, I think there’s going to be a fight.’ She was very funny.’

Sir Antony Jay, co-writer of Yes Minister and who also wrote the script of the groundbreaking 1969 TV documentary Royal Family, recalls that the Queen was not what he expected when he sat next to her at lunch. “She had just had her portrait painted and was sour about the artist rather than the portrait,” he says. “She was confident and cocky in a way you would never see in public.”

Head Coachman Colin Henderson remembers being with the Queen at the Windsor Horse Show when one of her grandchildren came up to her at the Royal Box. ‘The Queen said, ‘Did you have a nice lunch?’ and the child replied, “Yes, Grandma.” To which the Queen said, “I thought so – you’re all kidding.” ‘

A running gag involved Audrey Dellow, the organist for 40 years at the Royal Chapel at Windsor, who, according to Canon John Ovenden, vied with Her Majesty every Sunday over who wore the best hat.

“She could see the Queen in her mirror because the organ was almost opposite the royal pew,” recalled Canon Ovenden. “Everyone was in on the joke.”

Hats were also on display when the Queen visited Washington in 1991.

For the official welcome, she was hidden from view by the height of a lectern, meaning that only her eyes and hat were visible to onlookers. So the next day she began her address to a joint session of Congress by saying, “I hope you all can see me…”

Even in her final years, that mischievous humor remained firmly in place. Her appearance at last year’s G7 summit in Cornwall, eight weeks after Prince Philip’s funeral, was remarkable. It wasn’t just the warmth she radiated between some of the most bombastic personalities in the world, but also her sense of fun. As the leaders of the world’s major economies thronged for the official photos, she asked, “Should you have a good time?” with a knowing grin.

The subtext was clear: even if they weren’t, she certainly was. And her observation went a long way in demonstrating that she had emerged from her period of mourning and returned to the fray to participate fully in the affairs of the kingdom.