The Queen joked about being dressed by “Queen Victoria” during a stay at Balmoral – telling guests her great, great grandmother helped her get ready for a dinner.

The head of state was happy to let her dressers carry out their normal duties while wearing fancy dress ahead of a staff party – seeing the funny side of things.

Royal aide Angela Kelly recounts the story in her new book The Other Side of the Coin, and said the Queen insisted staff be allowed to wear their costumes to work at Balmoral, so they would not be late for their big night.

Investitures at Buckingham Palace
Angela Kelly the personnel dresser to the Queen (John Stillwell/PA)

Ms Kelly said the party was staged a few years ago and her assistant came as Queen Victoria, while another worker was John Brown, Victoria’s close friend and supporter.

The Queen’s personal adviser, curator and in-house designer, who was dressed as singer Cheryl Cole, said the Victoria costume “went down a treat with Her Majesty”.

She added: “Then, on her way down the stairs, we heard her explain to her guess ‘I’ve just been dressed by Queen Victoria and Mr Brown! I’ve been dressed by Queen Victoria herself, and John Brown. And I believe by Cheryl Cole’.”

The book also recounts how the Queen’s famous dry wit convinced her royal aid to change a new hair style.

Ms Kelly said she had updated her look, deciding to “stay blonde on top but go dark underneath which was the fashion at the time”.

She said: “When the Queen saw me the following morning, she looked at me and asked ‘have you ever seen a pint of Guinness?’

“I replied that, yes, I had, and her response was simply ‘hmm’ as if to say, ‘I will say no more’.

“Needless to say, I was straight down to the hairdresser the next day to change it back to blonde.”