Prince William, Prince Harry, Meghan Markle and Kate Middleton
Prince William and Kate Middleton's romance inspired Prince Harry to propose and marry Meghan Markle. Pictured: Prince William, Prince Harry, Markle and Middleton arrive at Westminster Abbey to attend a service to mark the centenary of the Armistice in central London on Nov. 11, 2018. Getty Images/Paul Grover

Prince William and Kate Middleton's romance may have inspired Prince Harry to find his own love and settle down.

According to Jessica Jayne's book "The Duchess of Cambridge: How Kate Middleton Became A Future Queen," the Duke of Sussex was a big supporter of the Duke and Duchess of Cambridge's relationship. Prince Harry revealed on his wedding day that he was inspired by his brother and sister-in-law.

At the reception, Prince Harry reportedly called his older brother "the dude" repeatedly and told everyone how much he "loved Kate like a sister." In addition, the Duke of Sussex confessed that Prince William and Middleton’s long romance had "inspired him."

Prior to Meghan Markle's arrival in the royal family, Prince Harry has always been close to Prince William and Middleton. The three worked closely together, earning them the moniker "royal trio."

When Prince William and Middleton tied the knot in 2011, the Duke of Cambridge broke royal protocol by choosing his brother to be his best man. It was the first time in history that a royal had named a best man because traditionally, they don't have one.

When it was Prince Harry's time to marry the girl of his dreams, he returned the favor by choosing his older brother to be his best man. And in their wedding reception, he announced how the Duke and Duchess of Cambridge’s romance convinced him to settle down.

According to recent reports, Prince Harry and Prince William are considering a formal division. Now that both have a growing family, they no longer rely on each other as before.

"The arrival of Meghan has changed the dynamic of the relationship in a fairly significant way," royal author Sally Bedell Smith told People. "It is inevitable and practical because it gives Harry and Meghan some freedom to build up their own collection of interests and charities."

"Meghan has very strong views on what she is interested in and that may be what Harry shares, but not what William and Kate share," Bedell explained.

According to royal commentator Claudia Joseph, the Duke and Duchess of Cambridge and the Duke and Duchess of Sussex will play different roles. "I think we are going to see more and more of William and Kate as 'team GB', for obvious reasons, and Harry and Meghan, I think, will be 'team Commonwealth,'" Joseph said.