Prince William arrived at Westminster Abbey on Friday to marry fairytale bride Kate Middleton as huge crowds and a global TV audience watched Britain's biggest royal wedding for 30 years.
Wild cheers erupted as a limousine carrying William, wearing a scarlet military tunic, and his younger brother and best man Prince Harry travelled from their father Prince Charles's official residence to the service.
The wedding is the richest display of pageantry since William's late mother Diana married Charles in 1981 and offers Britain's royal family a chance at renewal after Charles and Diana's bitterly public split.
The absence of Diana, who died in a car crash in Paris in 1997, will be keenly felt throughout the day, and Prince Charles's main spokesman Paddy Harverson said she was "always" in William's thoughts.
"But I think today is about the future and about Catherine and Prince William, and it's their day and I think you'll find it will go beautifully," Harverson told BBC television.
William Arthur Philip Louis - as Diana's eldest son and the second in line to the throne will be called during the service -- waved to the crowds with one white-gloved hand as he arrived at the abbey.
Guests were already packed inside, including footballer David Beckham, singer Elton John and "Mr Bean" actor Rowan Atkinson. Fifty members of the royal family and dozens of foreign royals were due after William.
At the 1,000-year-old building, the prince faced a nervous 45-minute wait for the arrival of Kate, the commoner he began dating at St Andrews university in Scotland eight years ago.
Queen Elizabeth II granted the couple the titles Duke and Duchess of Cambridge as a wedding gift earlier in the day.
Two billion people -- a third of the world's population -- are expected to tune in on TV and the Internet while thousands of campers transformed The Mall, the wide boulevard leading to Buckingham Palace, into a sea of Union Jack flags.
"They will make the monarchy fashionable again. It's good for the country," said Louise Akehurst, 25, an administrator from London.
William, a 28-year-old Royal Air Force search and rescue helicopter pilot, has long been seen as the great hope of the royal family for the future after a string of failed marriages and scandals.
Sandra Russell, 65, who is of French-British nationality, said she thought the marriage would be successful because Kate is "much older than Diana was at the time, much more mature and they are marrying for love."
"Charles was under the pressure of his family. People here are still angry at him, and Camilla (his second wife) too. I hope William will be the next king." Kate's mother Carole arrived at the abbey wearing a knee-length sky blue wool crepe coat dress by the late Catherine Walker, one of Diana's favourite designers.
But the first glimpse the world will have of 29-year-old Catherine Elizabeth, and her dress, will be at precisely 0951 GMT when she emerges from the exclusive hotel where she spent the night and climbs into a Rolls-Royce to head to the abbey.
She will take four minutes to walk down the aisle, which is lined with trees specially brought in to create the feel of an English garden. The service is due to begin at 1000 GMT, although it is the right of British brides to be several minutes late.
The Order of Service reveals that Kate will not promise to obey her husband in her marriage vows -- following in the footsteps of Diana, who married Charles on July 29, 1981 at St Paul's Cathedral. Charles and Diana divorced 15 years later. William and Kate's service will include a hymn played at Diana's funeral, which also took place in Westminster Abbey.
After the service, the newlyweds will travel in a horse-drawn open carriage from the abbey to Buckingham Palace where the couple will follow tradition by appearing on the balcony with the rest of the royal family and kissing.
Kate's dress has been a tightly-guarded secret, but a woman thought to be Sarah Burton, the creative director of the fashion house of late British designer Alexander McQueen, was seen entering the Goring Hotel where the bride was staying.
More than 8,500 journalists and technical staff are covering the wedding for a global audience.
And the world will join in the party. New York's iconic Empire State Building will be illuminated in blue, white and red in honor of the royal couple.