As a commoner marrying the future King of England, Kate Middleton had to face a lot of challenges before she was accepted into the royal family. However, a royal expert claims that even her husband "auditioned" her for her role as his consort before making the final decision.

In an appearance on ITV's documentary "The Day Will and Kate Got Married," released soon after the future monarch couple celebrated a decade of their marriage, royal expert Robert Lacey said: "It's been said that William was auditioning Catherine for her future role."

"And I think there's a truth to that. William is the future King of Britain and the Commonwealth and, like it or not, part of his job was to choose a consort who would do the job well," Lacey explained, as reported by The Mirror.

Many believe that William was determined not to rush into marriage given how his parents Prince Charles and Princess Diana's relationship fell apart when the latter couldn't adjust to the royal family. He reportedly wanted to make sure that his wife truly understood what she was getting into and would be able to survive.

William and Kate, who met as freshers at the University of St Andrews, dated on-and-off for eight years before the royal popped the question. Royal expert Katie Nicholls claims that their brief breakup in 2007 was also caused by Wiliam's fear to commit as he had started to feel "claustrophobic" in their relationship.

Meanwhile, palace courtiers did not make it easy for Kate, and gave her the cruel nickname "Waity Katie" while she was William's girlfriend in 2008, mocking her as she wasn't yet proposed to. However, Historian and author Sarah Gristwood claims that these same courtiers who reputedly once sneered at Kate are now "bowing the lowest" to her.

"She looks like the person who's going to have to play a big hand in the ongoing remoulding of the monarchy," Gristwood told Vanity Fair.

Meanwhile, sources told Mail Online that Kate's determination and confidence about her role in the British monarchy has grown since her brother-in-law Prince Harry and sister-in-law Meghan Markle quit as working royals last year.

"The Duchess is definitely doing things that are different and outside her comfort zone these days, and that's because she feels confident doing them," palace aides told the outlet.

Kate Middleton and Prince William
Kate Middleton and Prince William BRITTA PEDERSEN/AFP/Getty Images