Everyone knows that a meeting with the royals goes hand-in-hand with certain rules. One person who didn't seem to give a damn about these though? Michelle Obama.
During a 2009 reception, the then-First Lady threw the rulebook out of the window, going in to hug Queen Elizabeth II.
The breach of royal protocol took place on 1 April 2009 when Barack Obama made his first visit to the UK as US President to attend a G20 summit, and sent commentators into a frenzy.
Why did she do it? We've been left in the dark for nine years, but with the release of her new book, now we finally know.
In her memoir, Becoming, the 54-year-old reveals that she and Britain's monarch of 66 years had bonded over something that most women out there will be familiar with: sore feet after a long day wearing heels.
Describing the moment, the mother-of-two explained that her hug was a sign of affection, stating: "She shook her head. 'These shoes are unpleasant, are they not?' she said. She gestured with some frustration at her own black pumps.
"I confessed then to the Queen that my feet were hurting. She confessed that hers hurt, too. We looked at each other then with identical expressions, like, when is all this standing around with world leaders going to finally wrap up? And with this, she busted out with a fully charming laugh."
She continued: "Then I did what’s instinctive to me any time I feel connected to a new person, which is to express my feelings outwardly. I laid a hand affectionately across her shoulder. I couldn’t have known it in the moment, but I was committing what would be deemed an epic faux pas."
Obama's account of meeting the queen is the latest in a string of stories in her new book, where she writes about her career in law, her marriage, and her time serving in the White House.
It also delves into the turbulent world of American politics, with the former FLOTUS making her feelings on Donald Trump perfectly clear.
In the memoir, the 54-year-old accuses the president of putting her family in danger, naming the former businessman's unfounded claims that her husband was secretly a foreign-born Muslim as "crazy and mean-spirited" with an undercurrent of "bigotry and xenophobia hardly concealed."
"But it was also dangerous, deliberately meant to stir up the wingnuts and kooks," she writes. "What if someone with an unstable mind loaded a gun and drove to Washington? What if that person went looking for our girls? Donald Trump, with his loud and reckless innuendos, was putting my family’s safety at risk. And for this, I’d never forgive him."
Furthermore, she speaks out about Trump's now-infamous "grab her by the p***y" moment, claiming her "body buzzed with fury after hearing it".
She names the former reality TV star a "misogynist," comparing him to his rival Hillary Clinton, who she calls "an exceptionally-qualified female candidate."
Becoming was released on Tuesday and is currently No. 1 on Amazon.
