Queen Camilla used a shoe to hit a man who tried to touch her on a train, according to a new book about the monarchy.
The Queen told then Mayor of London Boris Johnson about the attack that occurred when she was a teenager, Power And The Palace claims.
Its author, the former Times royal correspondent Valentine Low, spoke to ex-Downing Street communications director Guto Harri who said Mr Johnson told him about a conversation at Clarence House in around 2008.
In an extract published in The Sunday Times, Mr Harri said the Queen and Mr Johnson “got on like a house on fire”.
“He (Mr Johnson) was making guttural noises about how much he admired and liked her,” Mr Harri said.
He went on to speak about the conversation between Camilla and Mr Johnson, about an assault that she said occurred when she was a schoolgirl.
“She was on a train going to Paddington – she was about 16, 17 – and some guy was moving his hand further and further…”
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Mr Harri said that after Mr Johnson asked what she did next, Camilla replied: “‘I did what my mother taught me to. I took off my shoe and whacked him in the nuts with the heel’.
“She was self-possessed enough when they arrived at Paddington to jump off the train, find a guy in uniform and say, ‘That man just attacked me’, and he was arrested.”
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The Queen has long campaigned against domestic violence and sexual abuse and has dedicated her royal charity work to supporting victims of sexual assault.
A number of years ago she championed the idea of wash bags for people who have been victims of sexual assault, an idea that has recently been revived.
Sky News has approached Buckingham Palace for comment.