Royal Wedding: Prince William and Catherine Middleton Kiss Twice on Balcony as World Watches

The royal newlyweds did not disappoint with their romantic balcony kisses.

April 29, 2011— -- Royal newlyweds Prince William and Catherine Middleton kissed twice on the balcony of Buckingham Palace in front of family and ecstatic crowds.

The married couple, who officially became the Duke and Duchess of Cambridge Friday morning, smiled and waved before thousands of screaming spectators and a worldwide audience of more than 2 billion people as they made the customary post-wedding appearance on the palace balcony.

In the most carefully choreographed of weddings -- with every moment planned to the second -- the couple's balcony kiss was the one wildcard, and it did not disappoint. The heir to the British throne first exchanged a short peck with his beloved bride and then leaned in to kiss her again about two minutes later. The Abbey bells rang, the overhead fighter planes hummed and heart-shaped balloons floated above. The crowd erupted in cheers and became a sea of waving flags.

At Westminster Abbey, William, 28, and Middleton, 29, held hands, gazed into each other's eyes and exchanged vows as if they were not surrounded by 1,900 guests in the historic cathedral. Middleton glowed in an ivory and white satin wedding gown, covered in delicate lace appliqué and full skirt, wearing a tiara. The only major moment missing from the fairytale service was a kiss.

Unlike most wedding ceremonies in the United States where the bride and groom kiss at the altar, royal newlyweds abstain from kissing during the service. Even outside the church, the kiss had long been viewed as an intimate and private moment until Prince William's parents, Charles and Diana, broke with tradition and spontaneously pecked on the balcony following their nuptials almost 30 years ago.

William and Middleton's first kiss as a married couple was short and sweet but seemed more natural than Charles and Diana's. Two minutes later, responding to chants from the crowd to "Kiss her again," the newlyweds locked lips, and William blushed ever so slightly.

The world weighed in on the iconic kiss on Twitter, with 98 percent of tweets dubbing the smooches a "#RoyalSuccess" versus a "#RoyalMess." Comments on Twitter skewed slightly negative after the first kiss, but turned celebratory after the second.

The only one who seemed not to share in the thrill and delight of the moment was Prince William's goddaughter, Grace Van Cutsem. The young bridesmaid, pictured below, covered her ears and pouted as the newly named duke and duchess locked lips on the balcony.

Watch a special two-hour edition of "20/20" tonight at 9 p.m. ET for a look back at all the highlights from the royal wedding with Barbara Walters.

After their balcony appearance, William and Middleton attended a lunch reception, hosted by the queen. They will return to the palace tonight to dance and celebrate, and will spend their first night as a married couple at Buckingham Palace.

The Most Famous Balcony in the World

The balcony at Buckingham Palace is perhaps the most prominent stage in the world.

"The balcony appearances are more than just PR," said ABC News contributor and British historian Robert Lacey. "They are the essence of modern contact between crown and people."

The 1858 wedding of Queen Victoria's oldest daughter, Princess Victoria, to Prince Friedrich Wilhelm of Prussia, was the first royal wedding to capture great public attention. It established the custom of the happy couple appearing on the palace balcony to be seen and cheered by the crowds gathered below around the Victoria Memorial.

Prince Charles and Diana's Balcony Kiss Broke Royal Tradition

Breaking with tradition, on July 29, 1981, Prince Charles and Lady Diana kissed on the Buckingham Palace balcony in front of throngs of rejoicing fans and a worldwide television audience of 750 million.

Charles sought the queen's nod of approval before he broke with royal protocol to turn and kiss his bride, to the delight of the jubilant crowd and a worldwide television audience of 750 million.

"With Charles and Diana ... [it] was the first time there was a kiss on the balcony because the people said, 'We want you to kiss,'" ABC's Barbara Walters recalled on "Good Morning America." "It was very quick. It was almost embarrassed. After all, she'd only met him 13 times before they got married."

Five years later, Prince Andrew and Sarah Ferguson elaborated the tradition set by Charles and Diana, passionately smooching in front of screaming spectators. However, their romantic kiss was not an indication that the marriage would endure; the couple announced their separation in 1992 and ultimately divorced in 1996.