“It’s the greatest ka-ching moment of all time.” So said CNN TV commentator Piers Morgan, as he and an estimated 2bn global viewers of the royal wedding – not to mention dress designers around the world – waited to discover who had made Catherine Middleton’s gown.

The answer: Sarah Burton for Alexander McQueen.

According to a statement issued by Clarence House, “Miss Middleton chose British brand Alexander McQueen for the beauty of its craftsmanship and its respect for traditional workmanship and the technical construction of clothing. Miss Middleton wished for her dress to combine tradition and modernity with the artistic vision that characterises Alexander McQueen’s work.”

A classic gown with powerful echoes of the famous dress Grace Kelly wore to marry Prince Rainier, the design consists of a lace overlay on a satin bodice and a skirt with a 2.7-metre train.

Other than French Chantilly lace combined with English Cluny lace, it was composed entirely of fabrics sourced in the United Kingdom, and embroidered by the Royal School of Needlework.

The choice was immediately applauded by the British fashion community. Designer Bora Aksu said, “The dress was absolutely right as Catherine looks straight out of fairytale. The style is timeless and will look just as stunning in many, many years to come. A great honour to British fashion.”

Designer Graeme Black said: “She is the Grace Kelly of our age. Britain loves the dress.”

Catherine Middleton’s decision will have immediate repercussions for Alexander McQueen, one of the smaller brands in the luxury group of conglomerate PPR.

Though famous within the fashion community for its dramatic runway shows, and the subject of worldwide coverage last year when its eponymous founder committed suicide, McQueen is only just reaching the size at which it can advertise. Its first, small campaign was planned for this autumn/winter.

Antoine Belge, luxury analyst at HSBC, said: “For such a brand, [the royal wedding] is a tremendous opportunity to attract intense media coverage it could never have financially afforded otherwise.”

The selection of McQueen also places a national halo around the brand, which shows in Paris and is owned by a French group, confirming it as one of the pre-eminent British fashion names on the global stage, and suggesting Ms Middleton may use her position to further the interests of the British fashion industry.

Finally, the dress also marks a very public coming out for creative director Sarah Burton, an unknown until she assumed the design helm of the company last May after Mr McQueen’s death.

Ms Burton said: “It has been the experience of a lifetime to work with Catherine Middleton to create her wedding dress . . . I am so proud of what we and the Alexander McQueen team have created.”

Though Ms Burton has remained largely in the background since her appointment, quietly evolving the label’s aesthetic from the aggressive genius of Mr McQueen in a more feminine, gentle direction, Ms Middleton’s gown should further enhance perceptions of the label’s growing accessibility.

The house’s range was further demonstrated by the dress Ms Burton designed for Philippa Middleton, maid of honour, a notably streamlined cap-sleeved long sheath in heavy crepe, with a draped cowl neck.

Robert Burke, chief executive of brand consultancy Robert Burke Associates, said: “The designer will have a world wide audience that only happens every new decades.

“A smart brand can double, triple or more their business in a short time.”