The royal bridal gowns, recently the subject of a major project by textile conservation experts from the Historic Royal Palaces charity, are very rarely on display,if ever. However six are unveiled today, to celebrate the forthcoming marriage  of Prince William  and Kate Middleton;  the collection reveals reveal a fascinating history of styles over a period of nearly 150 years..

The oldest dress in the collection belonged to Princess Charlotte, the only child of the future King George IV, when she married Prince Leopold of Saxe-Coburg, on May 2nd, 1816. The ankle-length design was seen as the height of fashion.

However 24 years later, Queen Victoria ignored the precedent, and picked a crinoline-style court dress in white silk-satin when she married Prince Albert of Saxe-Coburg. Princess Alexandra of Denmark married Prince Albert Edward, later Edward VII, on March 10th, 1893, wearing a white court dress of English silk, made by a London dressmaker, Mrs James of Belgravia. It was embellished with Honiton lace, in a design of roses, shamrock and thistles to represent England, Ireland and Scotland.

That gown sits in stark contrast to the plain minimalist Norman Hartnell-designed dress worn by Priness Margaret nearly 70 years later when the Queen's sister married the photographer Anthony Armstrong-Jones.

Princess Alexandra also chose Westminster Abbey for her wedding in April, 1963, but her dress was more intricate, with a slim column, and sprinkled with gold paillettes underneath magnolia lace, with a 21-foot train.

An estimated two billion will see Prince William and Catherine Middleton take their vows next Friday. All eyes will, of course, be on The Dress, and which influences it will reflect.

The historic wedding dresses are among the 10,000 items in the Royal Ceremonial Dress Collection. Queen Victoria's wedding dress will be publicly displayed in March 2012, in the new permanent exhibition at the refurbished Kensington Palace, 'Victoria Revealed'