All along, there was only one.

As Lady Diana became the princess of Wales, she wore the "fairy-tale wedding dress" she had asked for. With its ruffle-edge bare neckline, pouffy sleeves, frothy veil and absolutely endless train, it was the wedding gown every little girl (and older girls) dreams of wearing when she marries her Prince Charming.

In spite of rumors that there were several versions of the wedding gown of the century -- so a substitution could be made if the design of the dress was discovered -- David Emanuel said yesterday that "in fact there were never any [others] at all." He and his wife, Elizabeth, designed the dress.

"We wanted to throw off the scent," Elizabeth Emanuel told reporters at a press conference in London.

The gown was made of crisp ivory silk taffeta and old lace with a fitted, boned bodice and was totally hand-embroidered with tiny mother-of-pearl sequins and pearls. The sweeping train was 25 feet long, a staggering expanse that virtually blanketed the red carpet in St. Paul's Cathedral. The train, a far cry from the three-foot trains many American brides find cumbersome, was detachable and came off the dress for the reception at Buckingham Palace. Her low-heel shoes, which lifted the bride to just less than her husband's height, repeated the dress's lace and embroidery.

Diana, princess of Wales, sidestepped the tradition set by Queen Victoria of uncovering her face for the ride to the wedding. A sparkling coronet of diamonds from the bride's family anchored the gobs of tulle. Her hair was virtually unchanged from the cut that has become her signature, but was a trifle longer than in earlier pictures.

A small blue bow was put into the dress's waistband for tradition's sake, and a tiny horseshoe of 18-karat gold and studded with diamonds was sewn in for good luck. The dress was made from about 40 yards of silk and about 100 yards of net for the petticoats.

David Emanuel said that the dress was ivory because "white is desperately hard against most complexions." And yes, they were worried what Prince Charles would think of the gown. "He said he liked it very much," said David Emanuel. "You have the awful thing that the poor chap would go down the aisle and turn around and not like what he saw."

Just as Diana did not disappoint a soul with her modern fairy-tale appearance, the royal family played its storybook roles to the hilt:

The dashing prince of Wales in full dress Navy uniform complete with white gloves and hat, removed as he entered the church and returned to him to don again as he left;

Queen Elizabeth, as usual, in a big hat to inflate her height, and a traditionally dowdy dress with knife pleats springing from the bust;

The queen mother looking queen-motherly, trailing seafoam-green ostrich feathers from her hat;

The handsome and proud father of the groom, Prince Consort Philip, also in military uniform;

The mother of the bride, Frances Shand-Kydd, in standard MOB fare: printed chiffon in pale blue;

The bridesmaids, very young and enchantingly gowned, as if straight from a Gainsborough painting.

In fact, the Thomas Gainsborough show on exhibit in London at the time the Emanuels were asked to make the dress may well have inspired the young designers, who created the bridesmaids' dresses as well. Even the salmon pink Forever Amber hat with feathers the princess wore upon leaving for her honeymoon was a variation on mid-18th-century themes depicted by Gainsborough.

Wedding dresses by the Emanuels begin at about $5,000. However, such an elaborately embroidered, specially woven and extravagantly trained wedding gown would cost at least twice that. But there was no official word on the price tag. The Emanuels refused to discuss price yesterday -- or whether Diana had paid anything at all -- saying only that the dress was "priceless."

The new princess folowed a rather European tradition of dressing her young bridemaids in white. The bridesmaids' bright yellow sashes picked up the yellow of the Mountbatten roses in the cascading bouquets that also included gardenias, white orchids, lilies of the valley and freesia. The dresses were really miniatures of the wedding gown.

Dr. Carlotta Miles, a Washington psychoanalyst who was watching the live television broadcast of the wedding, said she was impressed by the engaging young bridesmaids in white. "Young bridesmaids accent [the bride's] purity in a time of great impurity," she said.

The bride's penchant for ruffles, apparent in all the recent pictures of her, including the controversial Emanuel black strapless dress she recently wore to a London benefit reception, carried over to her going-away costume. Ruffles edged the white organdy collar and cuffs on the short-sleeve jacket and dress of salmon pink that she wore with white hose and pink leather flats.

London bridal designers began making copies of the wedding dress immediately and a polyester version was in Debenhams department store by early afternoon. But their American counterparts have been far more nonchalant. "It's magnificent," said Priscilla Kidder, of Priscilla of Boston. "But we have something close to that in our line already."

Wally Wallace, who heads Bridal Designs by Wally, called any effort to reproduce the gown with a 25-foot train "ridiculous." But he was sure he could reproduce by machine the hand embroidery of the royal wedding dress. "I could get it done tomorrow in New Jersey."

The sketch of the wedding dress released by Women's Wear Daily the day before the celebration proved inaccurate and also proved the success of the secret preparations.

Still, the Emanuels had been concerned when they heard the trade magazine was writing a story.

"We were just loading up to go to Clarence House and the public relations lady said, 'Women's Wear Daily -- they've got it.' And I said, 'Oh my gosh, I can't bear it.'"

But WWD publisher John Fairchild yesterday said there had been questions about the accuracy of the report, and in fact their sketch turned out to be off the mark. "We were suspicious of the release," said Fairchild, "but got it too late to check with London." About the dress: "I like the girl better than the dress."