We're all used to the overblown saying 'So-and-so as you've never seen then them before' but this one really does live up to the billing.
For these fascinating photos show The Queen dressed as a pantomime PRINCE!
Taken in December 1941, the rare pictures show Princess Elizabeth as Prince Florizel in Cinderella when she was just 15 years old.
Her younger sister Princess Margaret – who was only 11 – starred as Cinders. Other photos show the two princesses starring in other pantos for the next three festive seasons, all performed in the Waterloo Chamber at Windsor Castle.
In 1942 the show was Sleeping Beauty, with the young Queen playing Prince Salvador and Margaret as Fairy Thistledown.
The following year saw a production of Aladdin, with Princess Elizabeth in the starring lead and her sister as Princess Roxana.
The final show in 1944 was Old Mother Red Riding Boots, with the young Queen as Lady Christina Sherwood and Margaret as the Honourable Lucinda Fairfax.
Photographs of the pantos - signed by the two princesses - have now been made public for the first time.
They are being sold as part of an archive collected by a Cyril Woods, who was a star pupil at the Royal School in Windsor and acted in the pantos.
He struck up a lasting friendship with The Queen and worked for the Crown Estate office before his death in 2001. His collection, which includes almost 60 pictures, is expected to fetch around £16,000 when they go under the hammer next week.
Senior valuer Chris Albury said: "This has to be the biggest collection of such photographs to ever be discovered and put up for sale.
"You see the odd signed photograph, and the odd programme, but to have this many it really is remarkable. It is a lovely collection because it really shows the end of childhood for the young princesses.
"I doubt that many of these photos are known or have ever been published. They have never been shown publicly. One assumes the Queen knew of it but Cyril didn't show it off."
The photographs are part of a collection of photos and letters that were left to two life-long friends of Mr Woods after his death.
Amongst them is a letter from the Queen to the wife of Hubert Tanner, headmaster at the Royal School.
Writing in September 1950 the queen thanks Mrs Tanner for a letter congratulating the young Queen on the arrival of Princess Anne.
Her Majesty wrote: "Her brother seems very fascinated by her. It seems very strange to actually talk about 'children'!"
Mr Albury added: "The Queen really takes the time to write these very personal letters, often including more detail and words than you would expect. You can see real friendship and it is impossible not to find them touching."
The auction takes place at Dominic Winter, Gloucestershire, on December 11.
You can see all the photos of Elizabeth and Margaret in panto below: