Standing beside Prince William at the altar, Prince Harry appeared to whisper to his brother, "She is here now" as Catherine Middleton prepared to make her long walk down the aisle. When she joined Prince William for the ceremony, he told her, "You look beautiful."
It was one of several touching moments amid the regal pomp and circumstance of Friday's royal wedding.
The father of the bride, Michael Middleton, gave a small smile as he accompanied his daughter, who shined in an ivory and white satin wedding gown. After they entered Westminster Abbey, Middleton turned to Catherine and asked, "Are you ready? You look great." Catherine beamed as she walked down the aisle, with the rest of the bridal party following in tow.
Pippa Middleton, Catherine's sister and maid of honor, was dressed in a gown of ivory-colored satin-based crepe. She led the bridal party down the aisle, holding the hands of the two youngest bridesmaids, Lady Grace van Cutsem and Lady Eliza Lopes, both 3.
Coming into and leaving the Abbey, Pippa picked up and carried the long white train on the bride's gown, made by designer Alexander McQueen's Sarah Burton.
When she first arrived, Lady Grace gave a little yawn and a little tug to her hair wreath, made of ivy and lily of the valley, before walking into the Abbey.
The bridesmaids, Lady Louise Windsor, 7, Hon. Margarita Armstrong-Jones, 8, and Lady Grace and Lady Eliza each wore four ballerina-length dresses using the same fabric as Catherine's wedding gown, adorned with a pale gold sash made of wild silk.
Page boys, Master Tom Pettifer, 8, and Master William "Billy" Lowther-Pinkerton, 10, were dressed in child-size officers uniforms in the style of Foot Guards officers worn at the time of the Regency (1820s). As they made their way from the Clarence House, a royal residence, in a series of escorted Bentleys, the children, smiling, waved to the crowd.
Both Prince William and Prince Harry, the best man, smiled and waved to the cheering crowd on their way from Clarence House to Westminster Abbey in an escorted Bentley, as the church bells began to toll.
Upon arriving, they were greeted by the dean of the Abbey and then walked down the red carpet-lined aisle toward the altar, side-by-side. The brothers then mingled and greeted guests.
Both were dressed in "stunningly handsome" army corp. uniforms, a supposed nod to their comrades serving in Afghanistan.
In selecting their wedding party, Catherine Middleton and Prince William waved away the heavy hand of royal tradition and chose their siblings to stand beside them at the royal wedding. The wedding party was announced on Feb. 14.
In a more modern twist, William chose his brother Prince Harry, 26, to be his best man, rather than a "supporter" (often two) like many royal grooms before him. The Times quoted royal sources in February saying, "William made the choice because the term 'best man' had more relevance to his life than the alternative."
Harry took on an extra role at the wedding: late-night after-party planner. He is reportedly throwing a post-wedding private party for 300 of Kate and William's closest friends and family that is expected to end with a "survivors" breakfast at 6 a.m. the following day.
"It may be a party taking place at Buckingham Palace, but rock, it will," said ABC royal contributor Katie Nicholl.
Third in line to the throne, Harry is a regular polo player and was promoted to the rank of captain of the British Army Air Corps on April 17.
ABC News' Bob Woodruff spoke with Harry in Svalbard, Norway, about the wedding while he was on an expedition to the North Pole last month.
"It's a big deal. It's not just a normal wedding," Prince Harry told Woodruff. "It's a really big decision for him to bring Kate into the family."
Harry sang Catherine's phrases and called her and his brother William "a classic match." He said his father, Prince Charles, was "over the moon" about the upcoming nuptials and had helped picked out the processional music.
Kate Middleton Chose Her Sister to Be Maid of Honor
Following a more American wedding tradition, Kate chose her sister, Philippa "Pippa" Charlotte Middleton, 27, to be her maid of honor. Traditionally, Brits give the role of bridesmaids to much younger girls and don't have a "maid of honor" but instead a "chief bridesmaid."
Garnering almost as much attention as the bride-to-be these days, Pippa, a graduate of the University of Edinburgh, was named No. 1 Society Singleton by Tatler Magazine in 2008. She also launched and runs a website called the Party Times, an online party planning magazine.
Rumors have been circulating that after Catherine officially joins the royal family, her sister will be included in her official princess entourage.
"The rumor is [Pippa Middleton] will become her lady-in-waiting," Tatler magazine editor Catherine Ostler told ABC News in March.
The role of lady-in-waiting usually goes to a friend or a relative. Princess Diana and William's current stepmother, Camilla, both enlisted their sisters for the job.
ABC News contributor Duncan Larcombe reported in the Sun that Michael Middleton and his wife, Carole, spent $41,000 to host a barbecue at London's Goring Hotel for family and friends who were invited to their daughter's wedding ceremony but not to the evening royal reception at Buckingham Palace.
Although Kate Middleton and her family have often been called commoners for their lack of royal blood, they are by no means "common." The Middletons run a very successful party business out of their home in the village of Bucklebury, outside London.
Nevertheless, it was believed they did not meet Queen Elizabeth and the rest of their daughter's future in-laws until last week.
The Youngest Bridesmaids: Miss Grace and Miss Eliza
The four remaining bridesmaids adhere more closely to British royal wedding tradition in that they are all of grade-school age and are fellow royals.
The adorable Lady Louise Mountbatten-Windsor, 7, the youngest of Queen Elizabeth's granddaughters, is one of Kate's bridesmaids.
With a headful of blond curls, she is the daughter of Prince William's uncle, Prince Edward and his wife, Sophie Rhys-Jones, who are the Earl and Countess of Wessex. Lady Louise was born with exotropia, a rare condition that causes a divergent squint. Sensitive to this issue, her parents have often kept her out of public view.
The Hon. Margarita Armstrong-Jones, 8, is another one of Kate's bridesmaids. The daughter of Viscount Linley, Margarita has melted the hearts of many since she was seen playing with her second cousin, Prince William, a few years ago at a Christmas Day walk to church at Sandringam. She will be celebrating her ninth birthday two weeks after the royal wedding.
Kate Middleton's two youngest bridesmaids -- Miss Grace van Cutsemis and Miss Eliza Lopes -- are both at the tender age of 3 and come with previous bridesmaid experience.
With a name almost bigger than she is, Miss Grace is Prince William's goddaughter. She served in the February wedding of Lady Catherin Percy, 27, the daughter of the Duke of Northumberland and friend to William and Kate.
Miss Eliza is granddaughter of Camilla, the Duchess of Cornwall, who revealed that Miss Eliza's favorite bedtime story is "Angelina and the Royal Wedding" and that the little girl likes to dress up as Angelina. Last April, Miss Eliza served at the wedding of Honor Benson, a family friend, and reportedly fell asleep during the ceremony.
Prince William's 'Unusual' Choice for Page Boys
Royal wedding tradition experts have said that one of the most noted breaks from tradition in the royal wedding party was in Prince William's "unusual" choice of page boys.
Master William Lowther-Pinkerton and Master Tim Pettifer are both young sons of members of the Buckingham Palace household, past and present, rather than fellow royals or sons of aristocratic friends.
Master William, also known as Billy, 10, is son of Princes William and Harry's private secretary and chief wedding planner, Jamie Lowther-Pinkerton and his wife, Susannah Richards.
Master Tom, 8, is the groom's godson and the son of the princes' former nanny and their father's personal assistant, Tiggy Pettifer. ABC royal contributor Katie Nicholl called William's choice was "rather nice" given his history with the Pettifer family.
"[William] was very close to Tiggy," Nicholl said. "After his mother died she became more of a mother figure to him."