An estimated two billion people tuned into the live broadcast in what may have been the most-viewed event in history.
The security operation was the largest since Charles and Diana's 1981 wedding, and the day went off without a hitch. Police dispersed scattered protests from antimonarchists and anarchists, and arrested 43 people for offenses including drunkenness, breach of peace, and theft, but the mood was overwhelmingly celebratory.
"Everybody's happy, everybody's united," said Sabry Darwish, 61, who was in the crowd along the parade route. "Everybody is behind the bride and groom."
Many praised the couple's rare combination of humility and grace. Kate was a commoner from a wealthy but middle-class family who actually worked for a living after graduating from college; William has long had his mother's touch in connecting to the public, and he surprised fans who slept on the pavement overnight by personally thanking them Thursday for braving the cold.
The prince, 28, even displayed a quality almost never seen among royalty: humor. Surveying the 1,900 guests filling the abbey in their wedding finery, he turned to his father-in-law, Michael Middleton, and quipped: "We're supposed to have just a small family affair."
After a reception at Buckingham Palace, William took his new wife for a spin, driving a dark-blue Aston Martin Volante festooned with ribbons, bows, and balloons - and a license plate that read "JU5T WED." It was the kind of display that made some wonder whether the couple just might bring the British monarchy back.
"It's a real turning point for the royal family," Nicki Hookings, 47, said at one of thousands of street parties across Britain to celebrate the national holiday.
For much of the world, the wedding was a dramatic reaffirmation of the beguiling star power of Kate, 29. Despite the pressure, she carried the day with an easy smile, youthful exuberance, and a sense of decorum that matched the event. And when it was all over, she curtsied easily before Queen Elizabeth II.
"It's one happy event in the world right now," said San Francisco lawyer Laura Claster, who traveled to London to be with the crowds. "It gives us a day of celebration to forget the troubles in the world."
The ivory-and-white satin gown worn by Kate was designed by Sarah Burton at Alexander McQueen and reminded some of the wedding dress worn by a princess from another era, Grace Kelly, of Philadelphia and Monaco. Kate wore a diamond tiara on loan from the queen, and her dramatic oak-leaf-shaped diamond earrings were a gift from her parents.
William, second in line to the throne after his father, wore the scarlet tunic of an Irish Guards officer, reinforcing his image as a dedicated military man. The uniform includes a forage cap, two sashes, and a tunic. The cap is embellished with the Irish Guard insignia - an eight-point star of the Most Illustrious Order of St. Patrick.
The long aisle leading to the altar was lined with maple and hornbeam trees as light streamed in through the high, arched windows. The soft-green foliage framed the couple against a red carpet as they recited their vows flawlessly before Archbishop of Canterbury Rowan Williams.
After a ceremonial drive around London in an open-topped horse-drawn carriage, the couple appeared with the queen and their wedding party on the balcony of Buckingham Palace, where the highly anticipated first - and second - kisses brought screams of delight from the crowd.
It was then that photographers from around the world captured one of the day's most memorable images: As the couple locked lips, 3-year-old bridesmaid Grace van Cutsem, William's goddaughter, held her hands over her ears and scowled as she tried to block the sound of Royal Air Force planes screaming overhead.
Earlier in the day, the queen had bestowed upon the couple their first royal wedding present: the titles of the duke and duchess of Cambridge.
The palace was holding two parties: one in the afternoon for 650 guests, and a dinner dance for 300 close friends.
Arriving for the latter, Kate pronounced it a "great day."
"I am glad the weather held off," she said, appearing radiant in a strapless, white satin evening gown.
The flag went down as the queen and her husband left the palace for the younger royals to party the night away - and for Harry to make his best man's speech away from his grandparents' ears.
The couple have been living in a modest house in Wales near the base where William serves as an air force search-and-rescue helicopter pilot, and will continue to do so after their honeymoon, which remains shrouded in secrecy.