Queen Elizabeth II’s wedding dress is on display at Buckingham Palace in a wide selection of her clothes that open to the public on Saturday, part of celebrations of the 90th birthday of the world’s oldest monarch.

“Fashioning a Reign: 90 Years of Style from The Queen’s Wardrobe,” part of the summer opening of the State Rooms at the palace, features clothing from her childhood to the present day and also the dress worn by Elizabeth for her coronation in 1953.

The unprecedented display also includes her christening gown and the eye-catching bright green wool-crepe and silk dress she wore at one of her 90th birthday celebrations earlier this year.

The display will also include a black silk velvet dress she wore to a 1956 film premiere where she met Marilyn Monroe and many of the queen’s distinctive hats.

Elizabeth is by far the oldest monarch in British history and last year she surpassed her great-great-grandmother Queen Victoria as Britain’s longest-reigning sovereign.

“The Queen is well-known for block color dressing using vivid and bold colors to ensure she is easily visible on important occasions,” Caroline De Guitaut, the exhibition’s curator, told reporters.

De Guitaut said the dresses reflected the multi-faceted role the Queen plays as sovereign not only of Britain but also of the Commonwealth states, as well as being commander-in-chief of the British army.

The curator said that hats also played an important role in making her easier to spot in large crowds, which is why they often have elaborate trimming.

The monarch’s preferences for headgear range from cloche hats made popular in the 1960s to the Breton style of the 1970s and 1980s.

Nowadays, she is rarely seen in public without a hat.

Details such as colors and design gained a whole other level of significance during her state visits.

“The Queen’s ensembles are carefully designed to ensure they are appropriate for the climate like the oriental-flower patterned dress Her Majesty wore to a state visit to Singapore,” De Guitaut said.

The State Rooms are opened to tourists who purchase tickets each summer.