At last, the moment the world has been waiting for: Kate Middleton revealed her wedding dress, a long-sleeved lace and ivory satin design by Sarah Burton, the creative director for the late Alexander McQueen.
Looking both modern and traditional, Middleton recalled another commoner who became royalty, actress Grace Kelly, who married Rainier III, the Prince of Monaco, and became The Princess of Monaco.
Designer Mark Badgley, who watched the wedding from his Long Island home with partner James Mischka called the dress a "classic Grace Kelly gown that appeals to modern brides."
"We thought it was perfection," Badgley told ABCNews.com. "It's that kind of gown that's going to stand the test of time."
Tim Gunn of "Project Runway" agreed that Middleton's dress recalled Grace Kelly's. "I find that to be a great compliment," Gunn told ABC News. "While there's similarities in the dresses ... I find the neckline (of Middleton's dress) to be very modern, very much of today."
Kimberly Lee Minor, the chief fashion strategist for bridal line Priscilla of Boston, echoed Gunn and Badgley, calling Middleton's gown a "modern take on Grace Kelly's dress."
"They have so many other similarities," Minor told ABCNews.com. "Grace was a commoner and became a princess. They both had their own career. They are both beautiful people and aspirational to many. And their sense of style clearly."
Minor said Middleton stayed true to herself. "She looked like Kate and a modern interpretation of a princess," she said. "She stayed appropriate but true too her womanhood and who she is as a modern woman."
Badgley, of the bridal line Badgley Mischka, agreed that Middleton seemed to have "struck the balance" between looking young and modern and wearing something suitable for the formal Westminster Abbey.
"Often times you can see that kind of gown with a closed-up jeweled neck," he said. "That would have been stuffy. It was nice that there was the tiniest touch of decolletage. It made it more modern, more sexy."
Middleton paired the dress with a tiara made by Cartier and loaned to her by Queen Elizabeth II. The 'halo' tiara was purchased by The Duke of York (later King George VI) for his Duchess (later Queen Elizabeth, The Queen Mother) three weeks before he succeeded his brother as King. The tiara was presented to Princess Elizabeth (now The Queen) by her mother on the occasion of her 18th birthday.
The tiara held in place a short veil, which Middleton wore covering her face.
Badgley called them the "perfect touch."
"We love that she wore her hair down," he said. "We love a glamorous bride."
Fashion lovers around the globe have been waiting for months for a glimpse of the year's most anticipated outfit, which has been shrouded in mystery and the subject of speculation almost since the day Middleton and Prince William announced their engagement.
Gunn called the dress "ravishing."
"She is not disappointing," Gunn said. The dress in my view is beyond anyone's imagination. Kate could not look more princessly or queenly."
In the hours leading up to the wedding, clues pointed to Burton. A woman wearing accessories favored by Burton -- a distinctive studded leather belt doubled through the belt loops of her jeans and ballet pumps -- was seen Thursday going into the Goring Hotel, the Middleton family headquarters, according to the U.K.'s Daily Telegraph.
The woman hid her hair and face under a fur "trapper" hat in an attempt to hide her identity from the swarms of photographers and television crews.
After finally revealing her identity, Burton gave a statement to The Guardian newspaper.
"It has been the experience of a lifetime to work with Catherine Middleton to create her wedding dress, and I have enjoyed every moment of it," she said. "I am delighted that the dress represents the best of British craftsmanship. Catherine looked absolutely stunning today, and the team at Alexander McQueen are very proud of what we have created."
Last month, the Telegraph reported that Middleton chose Burton "for the discretion afforded by her relatively low profile, as well as for her alternative take on elegance." Burton's work is said to have "caught Middleton's eye" when she designed an off-the-shoulder wedding dress for Sara Buys, a fashion journalist who in 2005 married Tom Parker Bowles, Camilla's son. Buys is reportedly friendly with Middleton.
Considered one of Britain's edgiest labels, a McQueen dress would be in line with Kate's interest in fashion. Signature McQueen looks included billowy dresses cut in hourglass silhouettes, frock coats paired with skinny pants, sharp, angular suiting, and darkly romantic gowns covered in intricate embroidery and lace.
Famous clients include Sarah Jessica Parker, Cate Blanchett, Kate Moss and Michelle Obama, who wore the so-called "Poppy" dress for a state dinner.
Badgley said he was not completely surprised by Middleton's choice of Burton. "I know that she's a fashionable girl," he said. "I kind expected that would be on her radar."
Burton, who grew up in Manchester, England, and graduated from Central Saint Martins in 1997, worked with McQueen for 16 years. She was considered McQueen's right-hand prior to his 2010 death and was head of design for the label's women's wear since 2000. Burton has been credited with completing the designer's autumn/winter 2010-11 collection in time for Paris Fashion Week in March, less than a month after his suicide.
Middleton has long been interested in fashion and design. She worked for the British apparel chain Jigsaw as an accessories buyer after graduating from St. Andrews University, where she studied art history. It was at St. Andrews where she modeled in a student fashion show and reportedly caught Prince William's eye in a see-through dress.
According to a Royal Palace press release about her wedding dress, Middleton worked closely in formulating the design.
The dress is made with ivory and white satin gazar. The skirt echoes an opening flower, with white satin gazar arches and pleats. The train measures around feet. The ivory satin bodice, which is narrowed at the waist and padded at the hips, draws on the Victorian tradition of corsetry and is a hallmark of Alexander McQueen's designs. The back is finished with gazar and organza covered buttons fastened by Rouleau loops. The underskirt is made of silk tulle trimmed with Cluny lace.
The lace appliqué for the bodice and skirt was handmade by the Royal School of Needlework, based at Hampton Court Palace. For the bodice, individual flowers were hand-cut from lace and hand-engineered onto ivory silk tulle to create a unique and organic design, which incorporates the rose, thistle, daffodil and shamrock.
Minor of Priscilla of Boston predicted that long sleeves will become a new trend in wedding dresses. Ivanka Trump and Nicole Richie both wore dresses with sleeves, but Middleton, whose wedding was watched live around the world, will take the sleeved dress to another level.
"This was the tipping point for sleeves on a gown," Minor said. "It was just beautiful, the lace with the handmade flowers was just soft enough. It's a perfect way to do sleeves. And you don't have to be 5'10, like Kate, to wear this silhouette."
Burton also designed the dress worn by Philippa "Pippa" Middleton, Kate Middleton's sister and maid of honor. The dress is made of a heavy, ivory satin-based crepe, with a cowl front and with the same button detail and lace trims as the bride's dress.
Minor said the dress was a hit. "Pippa was no lady in waiting," she said. "She was a chic bridesmaid. In her own right, she made a definitive statment. It was beautiful in such a different way, very chic, very modern, simple lines."
In addition to the bridal dress, there had been widespread speculation about the shoes that Middleton will wear. The Huffington Post reported that the bride-to-be commissioned four pairs of shoes for her wedding day, each with different heel heights. The lowest will be used to walk down the aisle at Westminster Abbey and are expected to be covered with multiple layers of silk and embroidery.
Middleton will reportedly change out of those shoes and into more festive heels for Friday afternoon and evening events, where she will perhaps, to the delight of the fashion-loving masses, debut a party-ready dress or two, too.
The palace confirmed that the wedding shoes were handmade by the team at Alexander McQueen of ivory duchesse satin with lace hand-embroidered by the Royal School of Needlework.