Sarah Burton, designer of Kate Middleton’s iconic gown, kept her mother in the dark about her latest creation as she resigns from Alexander McQueen. Unveiling the mysteries surrounding the infamous royal wedding dress, Claudia Joseph unveils the secrets.

It was a subtle tribute to the designer of her wedding gown: when the Princess of Wales discovered that Sarah Burton was stepping down this week as creative designer of Alexander McQueen, she donned a navy-blue suit by the fashion label.

She has the suit a blazer and cigarette pants in a variety of colours including white, black, and this summers ubiquitous colour Barbie pink, as well as owning numerous gowns and coat dresses.

But it is Kates wedding dress that has become the calling card of the designer, who has gone onto be named Designer of the Year and receive an OBE.

Kate is believed to have chosen Sarah Burton to create the worlds most talked about dress after being impressed by the Alexander McQueen dress that fashion journalist Sara Buys wore for her marriage to the Queens son Tom Parker-Bowles in 2005.

Miss Middleton chose British brand Alexander McQueen for the beauty of its craftsmanship, the Palace said in a statement at the time of the wedding.

According to Burton, the dress was a 50/50 collaboration between the designer and the royal, who is believed to have been inspired by the frock that the late actress Grace Kelly wore to her 1956 wedding to Prince Albert of Monaco.

Kate visited the Grace Kelly Style Icon exhibition about the Hollywood actress at the Victoria & Albert Museum in the year before her 2011 wedding and fashion pundits noticed parallels between the two gowns.

The dress, which featured a Victorian-style corset, which narrowed at the waist and was padded at the hips, underneath a lace bodice, was a closely guarded secret: the designer did not even tell her mother about it.

Even my mum called me and asked me: You would tell me, wouldn’t you?, the designer revealed afterwards.

The back of the gown, which had a modest train, of two metres and 70 centimetres, was finished with 58 gazar and organza covered buttons finished by Rouleau loops.

The lace was created by the Royal School of Needlework, which cut individual flowers the rose, thistle, daffodil, and shamrock from antique lace and appliqued them onto ivory silk tulle.

Embroiderer Amanda Ewing, who was part of the team that made the gown, said: We knew who it was for, but it was very secret. We had net curtains up, and cleaners were not allowed into the room and the code on the door was changed.

Kate teamed the dress with a 1936 Cartier Halo tiara, loaned to her by the Queen her something borrowed and a pair of diamond earrings, created by the jeweller Robinson Pelham her something new.

A gift from her parents, the drop earrings, which echo the Middleton family coat of arms, were shaped like oak leaves with a pav diamond acorn suspended in the middle.

Her wedding shoes, which were size five and a half, were made of ivory duchesse satin and adorned with lace and crafted by the Alexander McQueen team.

The late Chanel designer Karl Lagerfeld said at the time: The dress is classic and goes very well in the Westminster decor. It almost reminds me of (Queen) Elizabeths wedding, the royal weddings in the Fifties.

Sarah Burton joined McQueen straight out of Central St Martins College in 1997 the first question Lee (as McQueen was known) asked her was: Do you believe in UFOs?

Sadly McQueen, who was her boss, friend, and mentor, committed suicide in 2010 and Burton reluctantly took over the helm.

• How the Dress Like a Princess: The Secrets of Kates Wardrobe is published by Splendid Publications at 12.99