Prince William and Kate Middleton
Prince William and Kate Middleton broke a number of protocols on their royal wedding. Pictured: Prince William and Middleton smile following their marriage at Westminster Abbey on April 29, 2011 in London. Getty Images/Chris Jackson

Kate Middleton and Prince William broke royal protocol during their 2011 royal wedding.

The Duke and Duchess of Cambridge exchanged “I do’s” on April 29, 2011. When the couple decided to tie the knot, they didn’t follow some traditions of the royal family.

According to Marlene Koenig, British royal weddings don’t usually include a best man. Those who are with the groom are usually called “supporters.” However, Prince William assigned his brother Prince Harry to be his best man on his big day. The Duke of Sussex returned the favor by appointing the Duke of Cambridge as his best man when he married Meghan Markle on May 19, 2018.

In addition, Prince William ended the centuries-old royal protocol of not marrying a commoner when he asked Middleton to be his bride. In Jessica Jayne’s 2012 book “The Duchess of Cambridge: How Kate Middleton Became A Future Queen,” the author said that Middleton is the first “commoner” bride after over three centuries.

“All of those who have lambasted Kate and criticised her for being 'common' ate their words,” Jayne wrote. “Kate would be the first commoner to marry a prince in 350 years.”

During the Duke and Duchess of Cambridge’s wedding reception, Prince Harry gave a speech. Prince William’s brother was supposed to compliment Middleton’s “killer legs” in his “affection, warm and funny” message, but his then-girlfriend Chelsy Davy asked him to remove it because it might embarrass the bride.

Prince Harry teased Prince William in his message by saying that the future king had no “romantic bone“ before he met Middleton. So he knew that it was serious when he saw his big brother cooing down the phone at Middleton.

The soon-to-be dad also made the bride cry when he said that Prince William and Middleton’s decade-long romance was his inspiration. Prince Harry and Middleton were very close before Markle joined the royal family.

Unfortunately, the same event convinced Prince Harry’s girlfriend at the time that she was not meant to be a royal bride. Davy saw all of Middleton’s sacrifices and realized that she couldn’t do the same for Prince Harry.

After witnessing Prince William and Middleton’s royal wedding, Davy made up her mind. She knew that she couldn’t cut it, so she and Prince Harry ended their on-and-off romance that lasted for several years.