London (CNN) -- A treasure trove of old photos has revealed how Queen Elizabeth once took to the stage -- sometimes dressed as a boy -- in a series of holiday pantomimes during World War II.
The archives feature more than a dozen signed photographs of Princess Elizabeth and the late Princess Margaret, her younger sister, as the teenage stars in Christmas productions of the traditional plays at Windsor Castle in the 1940s.
A pantomime -- or "panto" as it is also known -- is a mixture of slapstick and music performed across Britain during the holiday season. They are typically based on children's stories and usually feature male leads played by women (and vice versa), comedic twists and audience participation.
After the outbreak of World War II in 1939, King George VI and Queen Elizabeth -- the current queen's mother -- spent most of their time in London while their daughters remained in Windsor, just outside the capital.
But at Christmas they would return to join a privileged audience at the luxury pantomimes their daughters starred in at the Royal School.
In 1941 Elizabeth, then 15, played Prince Florizel, the male lead, in a pantomime of "Cinderella", while 11-year-old Margaret took the title role. The following year the future queen starred as Prince Salvador in "Sleeping Beauty" with Margaret as Fairy Thistledown.
In 1943 Elizabeth won her first title role in "Aladdin" with Margaret as Princess Roxana. The next year the royal sisters starred as Lady Christina Sherwood and the Honorable Lucinda Fairfax, respectively, in "Old Mother Red Riding Boots. "
The fascinating images are owned by the estates of Hubert Tannar, an amateur actor and headmaster of the school the princesses attended, and Cyril Woods, who shared the stage with the young Windsors and became a friend of the future queen during rehearsals.
The archive of royal pantomime photos -- along with documents, Christmas cards and over twenty letters from the Queen to Tannar's widow -- are expected to fetch thousands of dollars at auction next week.
"This is the best royal archive I have ever handled," said Chris Albury, the senior valuer at Dominic Winter Auctioneers, based in Gloucestershire, England.
"The pantomime albums are highly atmospheric and you can see both princesses growing from childhood to adulthood, but the albums are further dramatically charged when you consider the wartime backdrop to these luxury pantomimes performed at Windsor Castle."