The campers are already here, opposite Westminster Abbey, some pitching tents days early for a firsthand glimpse of the most-watched wedding on Earth. Mobs of foreign journalists are tripping over themselves to get the cute older couple in the Union Jack umbrella hats and the woman with the King Charles spaniel in a tiara. Non-British royal pilgrims are filling the streets of London with Malay and Spanish, Japanese and American English.

They are here for Prince William and Kate Middleton, but also the red-carpet guests of British blue bloods, the crowned heads of Europe, David Beckham and Elton John. Anderson Cooper, Katie Couric and Piers Morgan are on location. Tim Gunn and his film crew have been circling the abbey in an open carriage. Australian cross-dresser Dame Edna, “reporting” for “The Tonight Show With Jay Leno,” is stalking the streets outside, more interviewee than interviewer. Buckingham Palace, bowing to the great American media hordes, has agreed to turn the lights out an hour and half late so the TV anchors can get extended night shots. Even the queen nods to U.S. ratings.

Perhaps more than any other single event, the royal wedding Friday is exposing the members of the British royal family for what they really are: the original global celebrities. Despite the occasional grumbling from lads in the pub about those privileged freeloaders in Buckingham Palace, three out of four Britons still back the monarchy. Given the worldwide media frenzy over a wedding — even the proud republic of France is going gaga, with three national channels broadcasting live — it is easy to see why.

Although the sun set long ago on the British Empire, the royals, for all their foibles, still give this quaint and foggy land outsize importance, making it so the eyes of the world are focused on a marriage that would otherwise be a 28-year-old air force pilot getting hitched to a 29-year-old Internet party supply heiress. In the end, it works out cheap for the British: You cannot buy this kind of publicity.

“Oh, you can see it in this wedding! Never has one family so defined one country,” beamed Christopher Warren-Green, who will conduct the London Chamber Orchestra at Westminster Abbey on Friday. “Never has one family been so well known — and so watched — by the world.”

Austere — relatively

The royals will sing for their supper Friday, offering up a show of pomp and circumstance as only the House of Windsor can. Bowing to modernity and lean times in Britain — the nation is undergoing a historic round of austerity and budget cuts — this union is billed as an affair slimmed down from the last royal event of this scale: the glamorous nuptials of William’s parents, Prince Charles and Princess Diana, in 1981.

But slimming down for the royals still means one big to-do. A medieval abbey “dressed” with a living avenue of 20-foot maple trees, the London Chamber Orchestra strumming in the wings. An early-morning rehearsal on Wednesday involved 1,000 military personnel, the Royal Household Cavalry and 160 horses.

Sure, William and Kate are having a “wedding buffet” instead of a formal sit-down breakfast, and the bride will arrive in a vintage Rolls-Royce instead of a carriage. But barring the infamous clouds of London raining on their parade, the couple will still be hauled through the streets after their vows in the same open glass carriage that brought Diana to St. Paul’s Cathedral. For the luckiest of guests, the queen is hosting 650 for canapes and drinks, and Prince Charles is having a lavish dinner for 300. Reportedly, it will be followed by disco dancing — complete with mirrored ball — at Buckingham Palace that night.

Prince Charles is footing the bill for the majority of the wedding, with the well-to-do if non-noble Middletons chipping in an undisclosed sum. But the British taxpayer is still set to pick up pricey security costs, including overtime for the 5,000 police officers scouring the route Friday.

For some here, that is a bone of contention. Although the British still overwhelmingly back the monarchy, polls show one in three saying they do not care about this wedding. Fed up with the fuss, some Londoners have used the national holiday Friday to get out of Dodge.

But for others, the event is an echo of the dreams dreamed in 1981, before the marriage of Charles and Diana fell apart, before Diana died. Royalists are hoping William and Kate bring back some of the luster lost after the death of Diana, and call the state cost of the royal wedding a small price for one heck of a show.

“I know some people say they don’t care, but honestly, I think they care more than they admit,” said Cheryl Ptolomey, 60, camped out in front of the abbey with her daughter and the cremated remains of her mother, who was a die-hard Diana fan. “For me, I felt I had to be here. With all the wars, with all the austerity, I needed this. And I just had to. This is Diana’s son.”

Royal coattails

You cannot put a price tag on this family. For British brands, the royals amount to fabulously long coattails to ride. Take, for instance, a party this week at Lancaster House — part of St. James’s Palace. A soloist crooned “I Dreamed a Dream” inside a gilded hall as foreign journalists, feted with champagne and quail eggs, were invited to shuttle past elegant booths of British companies bestowed with a royal seal of approval, known as a “royal warrant.”

Those warrants sprinkle each with a royal stardust that sends a certain class of commoner worldwide agog. Said Alan Bennett, owner of the Savile Row tailor Davies & Son, which sells suits for up to $11,500: “With foreigners, it gives us credibility. . . . If you are a Russian oligarch, you know where to go.”

That does not mean the royals are always a gracious or forgiving bunch. Fourteen years after Diana’s funeral — when her brother seemed to rap the family on the wrist for its behavior — the Spencer family is still invited to Friday’s wedding. But it is seated on the bride’s side. Asked to respond, a royal spokeswoman quipped: “The seating plan is as it is; we’re not going to provide a comment.”

London hotels haven’t quite sold out, but hotel occupancy has jumped to 82 percent for the wedding, up from 76 percent last April. They have filled up with the likes of three Washingtonians, aptly named Cathy, Kathryn and Katherine.

One commentator on the BBC, marveling that mobs of foreigners would travel in for the wedding of British royals, called the rush a case of the three F’s – the fixated, the fanatic and the foolish. But for the three Kates, there is no mystery in their pilgrimage.

Sitting in a Green Park pub and mapping out their wedding plan, Cathy St. Denis, a Department of Transportation worker, outlined their mission: “See the dress. See the kiss.”

Kathryn Greenberg, who works in philanthropy in Washington, tried to further explain.

“You come over to the U.K., and they actually have princesses. Real princesses,” she said. “And we don’t have to pay for them,” just enjoy them.

But Katherine Miller, a Washington communications consultant, summed it up: “Let’s be honest. It’s like the World Cup for women.”

Staff writer Monica Hesse and special correspondent Karla Adam contributed to this report.