Question: What year was the person who designed Catherine, Duchess of Cambridge's wedding dress born?

Context paragraphs:
Wedding dress of Grace Kelly: The wedding dress of the American actress Grace Kelly, worn during her wedding to Prince Rainer III of Monaco on 19 April 1956, is cited as one of the most elegant and best-remembered bridal gowns of all time, and one of the most famous since the mid 20th century.  One author describes the dress as "adding to the marital fervor and elevating matrimonial fashion" and a major influence on women who strove to "emulate Kelly's peau de soie and lace masterpiece".  It was designed by Helen Rose of MGM.  The dress consisted of a bodice with an attached under-bodice and skirt support.  There were two petticoats, one being an attached foundation.  The wedding attire included a headdress, veil, shoes and the lace- and pearl-encrusted prayer book which she carried down the aisle.  To celebrate the 50th anniversary of the wedding, the Philadelphia Museum of Art (which now owns the dress) displayed it at the museum between 1 April and 21 May 2006 and reported it to have been arguably its most popular exhibit.

Wedding dress of Queen Victoria: The wedding dress of Queen Victoria was worn by Victoria, Queen of the United Kingdom, at her wedding to Prince Albert of Saxe-Coburg and Gotha on 10 February 1840.  She selected a white dress, which was considered an unusual choice at a time when colours were more usual, made from heavy silk satin.  The Honiton lace used for her wedding dress proved an important boost to Devon lace-making.  Queen Victoria has been credited with starting the tradition of white weddings and white bridal gowns, although she was not the first royal to be married in white.

Sarah Burton: Sarah Jane Burton, OBE (née Heard, born 1974) is an English fashion designer, currently creative director of fashion brand Alexander McQueen.  She designed Catherine Middleton's wedding dress for her wedding to Prince William, Duke of Cambridge in April 2011.  In 2012, she was named in Time 100, an annual list of the 100 most influential people in the world according to "Time".

Wedding dress of Kate Middleton: English designer Sarah Burton, creative director of the luxury fashion house Alexander McQueen, designed the bridal gown worn by Catherine, Duchess of Cambridge (née Middleton), at her wedding to Prince William, Duke of Cambridge, on 29 April 2011.

I Found The Gown: I Found The Gown is an American wedding dress shop reality series airing on TLC as part of that network's Friday evening "wedding block" of programming.  The series films at "VOWS Bridal Outlet", a discount wedding dress shop in Watertown, Massachusetts in suburban Boston which has existed since 1992.

Wedding dress of Sarah Ferguson: Sarah Ferguson wore a dress made from ivory duchesse satin and featuring heavy beadingfor her wedding to Prince Andrew, Duke of York on 23 July 1986 at Westminster Abbey.  Designed by Lindka Cierach, the beadwork incorporated various symbols including hearts representing romance, anchors and waves representing Prince Andrew's sailing background and bumblebees and thistles, which were taken from Sarah Ferguson's family crest.  Copies of the dress, including the motifs specific to the royal family, went on sale in stores just hours after the end of the wedding.Influenced by the wedding dress of Lady Diana Spencer, a notable feature of Sarah Ferguson's 17 foot long train was the intertwined initials A and S sewn in silver beads.  The head-dress and bouquet, fabric rosettes or artificial silk flowers were used to adorn the gown itself.  Ferguson was pleased with the dress, describing it in her 1997 memoir, "My Story", as "an exquisite creation I'd lost twenty-six pounds to fit into.  Lindka was a genius; I knew she could make the most flattering gown ever, and she had.  It was amazingly boned, like a corset. "Hair stylist Denise McAdam and make-up artist Teresa Fairminer attended to the bride, while florist Jane Packer designed the bouquet.  The ivory silk wedding dress became the season's most sought-after style.

Wedding dress of Princess Elizabeth: The wedding dress of Princess Elizabeth was worn by the future Queen Elizabeth II at her wedding to Philip Mountbatten, Duke of Edinburgh on 20 November 1947 in Westminster Abbey.  Given the rationing of clothing at the time, she still had to purchase the material using ration coupons.  The dress was designed by Norman Hartnell.  Hartnell's signature was said to be embroidery, and he enjoyed "working with soft, floating fabrics, particularly tulle and chiffon, and with plain, lustrous silks".  The dress was made of soft Damascus Prokar, with a high neckline, tailored bodice and a short train.

Trash the dress: "Trash the dress", also known as "fearless bridal" or "rock the frock", is a style of wedding photography that contrasts elegant clothing with an environment in which it is out of place.  It is generally shot in the style of fashion or glamour photography.  Such photography often takes place on a beach, but other locations include city streets, rooftops, garbage dumps, fields, and abandoned buildings.  The woman often wears a ball gown, prom dress or wedding dress, and may effectively ruin the dress in the process by getting it wet, dirty, or, in extreme circumstances, tearing or destroying the garment.

Wedding dress: A wedding dress or wedding gown is the clothing worn by a bride during a wedding ceremony.  Color, style and ceremonial importance of the gown can depend on the religion and culture of the wedding participants.  In Western cultures, brides often choose white wedding dress, which was made popular by Queen Victoria in the 19th century.  In eastern cultures, brides often choose red to symbolize auspiciousness.

Wedding dress of Princess Margaret: The wedding dress of Princess Margaret, the sister of Queen Elizabeth II, was worn at her wedding to photographer Antony Armstrong-Jones on 6 May 1960 at Westminster Abbey.  The wedding dress was designed by Norman Hartnell, the favoured couturier of the royals, and was made from silk organza.  The skirt comprised some 30 metres of fabric.  Hartnell specifically kept the adornments of the dress such as the crystal embellishments and beading to a minimum in order to suit Margaret's petite frame. " Vogue" described the dress as "stunningly tailored".  Another author called it "a study in simplicity".  In 1960, "Life" magazine named it "the simplest royal wedding gown in history".  It has also been described as one of Hartnell's most beautiful and sophisticated pieces.

Supporting paragraphs: Wedding dress of Kate Middleton Sarah Burton
Answer: 1974