Photos of Queen as a baby mark her 84th birthday

The images show a seven-month-old future monarch, then Princess Elizabeth, posing for cameraman Marcus Adams – a leading child photographer of his day.

The tousle-haired royal is pictured barefoot in a white dress and is also photographed separately with her parents, the Duke and Duchess of York, later George VI and Queen Elizabeth, on December 2 1926.

Two of the images became prized possessions of the Queen Mother and were kept in a double-frame leather picture case. One shows the seven-month-old gazing into the camera while in the other she smiles while being held by her mother.

The pictures of the infant are part of a series featured in a new book –Marcus Adams: Royal Photographer and are thought not to have been seen in public for many years.

Some of the prints and the leather frame will be displayed at a forthcoming exhibition at Windsor Castle that also chronicles Adams' work.

Adams created a unique record of two generations of royal children between 1926 and 1956, presenting a new, relaxed image of the monarchy.

When Princess Elizabeth's parents went on a six-month tour of Australia and New Zealand, she remained behind but returned to Adams' studio in January 1927 for another photo session.

A note written by Clara Knight, the Princess's nurse, which was sent to the King and Queen overseas, has been published for the first time and can be seen at the new exhibition.

Princess Elizabeth Alexandra Mary was born at 2.40am on April 21 1926 – the first child of the Duke and Duchess of York – at 17 Bruton Street, the Mayfair home of her mother's parents, the Earl and Countess of Strathmore.

She is great-great-grandchild of Queen Victoria, the last female sovereign. The Queen is grandmother to eight grandchildren.

The octogenarian has two birthdays – her actual one today and her official one in June, which is celebrated with the Trooping the Colour parade.

The monarch will be spending her day privately at Windsor Castle. Union flags will be flown above Government buildings from 8am until sunset in her honour.

The Marcus Adams book is published today and the Windsor Castle exhibition open on Saturday and runs until February 6 next year.