It is hard to believe that a sartorial legacy which ended in 1997 would have a lasting effect on fashion today (1 July) – on what would be Princess Diana's 55th birthday.

The master of royal style, Diana held power in her outfits whether it was the demure flowing gowns that she wore in her early marriage or the overt, powerful designs she paraded in once she had divorced from Charles in 1996. The sentiment: 'clothes maketh the (wo)man' had never rung truer.

Aside from the prowess and bravado of her couture designs, from the likes of the Emanuels and Catherine Walker, it was Princess Diana's sartorial ability to fit any situation with ease that made her a fashion icon. Moving from royalty to philanthropic humanitarian, her signature altered from the neat skirt-suits to chinos and a crisp shirt which came to embody her commitment to any cause.

Princess Diana's ability to dress for any occasion without ever seeming forced is an ability Kate Middleton is also becoming a master of. Savoir-faire mixed with a wicked sense of fun, Diana left us with a vast collection of iconic looks to treasure:

Princess Diana at White House in 1985
The iconic Victor Edelstein off-the-shoulder velvet gown Diana wore to the White House in 1985 – which she wore when dancing with the actor – is known as the 'John Travolta dress'. It sold for £240,000 at Kerry Taylor Auctions in 2013Reuters
Princess Diana, Serpentine Gallery
Princess Diana at the Serpentine Gallery, London, in a dress by Christina Stambolian – June 1994Jayne Fincher/ Getty Images
Princess Diana
Princess Diana in a bespoke tartan design by the Emanuels that she wore in Venice, Italy, 1985Tim Graham/ Getty Images
Princess Diana Kate Middleton
Princess Diana in one of the 1,000 designs she owned by couturier Catherine Walker. The pink sequined ivory crepe gown with asymmetric neckline was worn at a banquet given by President Collor at the Itamaraty Palace while on a State visit to Brazil, 23 April 1991Getty
princess diana best looks
While Diana was modestly dressed at most occasions, she also knew how to create a stir even with the most simple looks. The princess chose a fabulous plunging neckline gown to wear to accept the UCP Humanitarian award presented to her by Henry Kissinger and General Colin Powell in December 1995.Getty
princess diana best looks
Even in the heat, this safari suit with oversized gold buttons saw Princess Diana doing effortless chic during a visit to the Great Pyramid of Giza in May, 1992Getty
princess diana best looks
Even on a relaxed day Diana pulled off casual wear in style, pairing tangerine cycle shorts with a slouchy sweater and oversized sunglasses as she headed home from her health club in November 1996. Later that day she made her renowned appearance on Panorama to discussed her life with Charles and his adulteryGetty
princess diana best looks
Diana layers a Japanese kimono over her vibrant polka-dot wrap dress during her first visit to Kyoto, Japan in 1986Getty
princess diana best looks
Demure but cheeky as Diana poses for a photo in a mixed print blouse and white pencil skirt with bright green obi belt in front of Christ the Redeemer in Rio de Janeiro in April 1991Getty
princess diana best looks
A vision in white: A sleek, white suit that could have been plucked from Jackie Kennedy's wardrobe while visiting the Sacred Heart Hospital in Sydney in April 1991Getty
princess diana best looks
A young Diana relaxes with Prince Charles in a loose pink dress and matching hat with bow detail during their first official Australian tour together in 1983Getty
princess diana best looks
Sultry dark-eyed make-up and slick hair with her signature choice of diamond-and-sapphire jewels and a plunging gown – Diana arrived in style at the 14th Annual Council of Fashion Designers of America Award Gala in January 1995Getty
princess diana best looks
Diana's playful approach to style allowed her to fit in anywhere, even with Vogue's high priestess Anna Wintour and designer Ralph Lauren (R) among others at a benefit gala in 1996. Arriving at the White House, this was her first appearance after her divorce from Charles.Getty
princess diana
The lavish silk design by David and Elizabeth Emanuel that Diana wore for her wedding to Prince Charles in 1981Getty
princess diana best looks
Princess Diana in a graphic monochrome skirt suit and striking hat as she poses with sons Harry and William, and Prince Charles to watch VJ Day parade in 19 August, 1995Getty
princess diana
In a pink mini skirt suit with blue trim as she meets with a patient at mother Teresa's Missionaries of Charity in Calcutta during a six-day visit to India, February 1992Getty
princess diana best looks
Diana looked relaxed yet stylish in a pair of simple chinos and white shirt as she attended an engagement at British Red Cross mission in Luanda (Angola) to highlight the danger of landmines in January, 1997Getty
princess diana best looks
A simple T-shirt and sunglasses look on the beach in the West Indies in 1993 ensured she appeared just like every other mother playing with their childrenGetty
princess diana best looks
Enjoying some time away on the slopes in a green one-piece with sons William and Harry during a pre-Easter break in Lech, Austria, 1991Getty
princess diana best looks
Appearing enigmatic even among film stars as Diana poses for a photo with screen legend Alec Guinness during the 40th International Film Festival, 15th May 1987Getty
princess diana best looks
Attending a commemoration service for the 50th anniversary for the Battle of the Atlantic in a fittingly nautical look, May, 1993Getty
princess diana best looks
Diana looked as poised an elegant as the effortlessly stylish then First Lady Nancy Reagan – pictured with husbands President Ronald Reagan (L) and Prince Charles (R) in 1985Getty
princess diana best looks
Meeting French SFOR soldiers at Sarajevo airport in August 1997, this was taken only weeks before the princess died in Paris.Getty