"Fashioning A Reign: 90 Years of Style From The Queen's Wardrobe", the latest exhibition detailing the Queen's 90 years as monarch opens at Buckingham Palace on 23 July. The palace opened briefly today (4 July) to give a preview of the exquisite pieces that will be going on display at the end of the month that illustrate the Queen's life.

The exhibition which will showcase incredible pieces including the Sir Norman Hartnell designed gown that the Queen wore for her marriage to the Duke of Edinburgh in 1947 as well as the exquisite Coronation gown Elizabeth II wore in 1953, also by Sir Norman. However, the preview focused on a range of pieces most likely never seen by the public before from overalls worn during the then-Princess Elizabeth's time spent in the Auxiliary Territorial Service during World War Two and a range of designs from British fashion icons like Hartnell and Hardy Amies.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Caroline de Guitaut, Senior Curator at The Royal Collection, poses for a picture in the White Drawing Room with the preview pieces from the forthcoming 'Fashioning a Reign' exhibitionIan Gavan/ Getty

Caroline de Guitaut, the Senior Curator at The Royal Collection presented the pieces inside a palatial white drawing room within Buckingham Palace.

Speaking to Vogue back in April, De Guitaut was very enthralled by the forthcoming exhibition. "The Queen transcends fashion but her clothes continue to reflect it," she said.

"She is completely involved in her wardrobe and works with leading British couturiers of the day but will reject designer's sketches if she doesn't like them. Consistently elegant, she dresses in bright, visible block colours, often with a complementary hat but note that we rarely see her in pattern."

fashioning a reign
Ian Gavan/ Getty

One of the more unexpected pieces on show is a pair of Auxiliary Territorial Service overalls and cap in a heavy wool felt. Leaving behind her embellished eveningwear during the second world war, the then Princess Elizabeth wore these overalls whilst serving in the wartime ATS.

Queen 90th birthday
18 April 1945: Princess Elizabeth wearing overalls to change the tyre of a vehicle whilst training as an ATS Officer during World War TwoCentral Press/Hulton Archive/Getty Images

Whilst the Queen stays true to her twinset dress and coat combination these days, her past was brimming with awe inspiring designs by some of the British fashion industry's finest. A staunch backer of UK design, the Queen was a firm supporter of the work of Sir Norman who was presented with a Royal Warrant as dressmaker to Queen Elizabeth II in 1957.

A pale blue and gold one-shoulder silk evening dress by Hartnell is also on display as part of the collection. The dress is an exquisite example of the craftsmanship that went into the eveningwear for the royals and a true view of traditional British couture.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Ian Gavan/ Getty

Another couturier to be displayed is Hardy Amies, who created a sophisticated turquoise blue evening dress with silver thread embroidery.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Ian Gavan/ Getty

A piece from the 1960s Hardy Amies' designs were slightly more streamlined than those of Hartnell and bore a more modern aesthetic. However their detail is equally as breathtaking as you can see with the intricate sequin and bead embellishment.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Ian Gavan/ Getty

A more directional dress coat by Sir Hartnell is also on display with angular diamond details, complete with matching hat in a striking royal blue silk.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Ian Gavan/ Getty

The most modern piece on show is the canary yellow coat designed by the Queen's current favourite Angela Kelly. The neat, streamlined design with co-ordinating wide-brim hat was worn by her majesty for the trooping the colour ceremony back in 2012.

'Fashioning A Reign: 90 years Of Style From The Queen's Wardrobe'
Ian Gavan/ Getty

The piece is far more representative of the Queen's tastes as she is now compared with the sartorial style of her youth. The full exhibition which opens on the 23 July will segue through the nine decades of her life.

fashioning a reign
The Queen in her Angela Kelly outfit at the Trooping the Colour ceremony in 2012Getty

"Fashioning A Reign: 90 Years of Style From The Queen's Wardrobe" runs between 23 July and 2 October as part of the summer opening of the state rooms at Buckingham Palace.

The exhibition continues at the Palace of Holyroodhouse (21 April-16 October 2016) which will focus on the role of tartan in the Royal wardrobe, and Windsor Castle (from 17 September 2016-8 January 2017), which looks at the contrast between official royal gowns and the fancy dress costumes of Princess Elizabeth.

For more information, go to: royalcollection.org.uk