Prince William, Kate Middleton Decided To 'Up Their Game' After First Joint Engagement With Meghan Markle: Book

Prince William and Kate Middleton had a realization during their first official engagement with Prince Harry and Meghan Markle in 2018, according to a book.

The Prince and Prince of Wales made their first joint engagement with Prince Harry and Markle at the inaugural Royal Foundation Forum in February 2018, months before the Duke and Duchess of Sussex's royal wedding. It was the first time the four royals, dubbed the "Fab Four," took the stage together to showcase the projects headed by Prince William and Prince Harry in 2011. Middleton joined the charity work after she married Prince William, Today reported.

According to Vanity Fair editor Katie Nicholl in her new book "The New Royals," the outing left some impressions on the Duke and Duchess of Cambridge. Markle's presence reportedly made them realize that they had to "up their game."

"It was, according to one aide, the moment William and Kate, who was heavily pregnant, realized they needed to up their game," Nicholl wrote, Entertainment Tonight reported. "The Cambridges had already signaled their intention to be more than 'ornamental royals' and had, along with Harry, made a huge success of their mental health campaign Heads Together."

She continued, "But Meghan was the breakout star of the foursome. She was polished, passionate, and funny, using all her TV-honed skills to present her case. That was a wake-up moment for William and Kate when they realized that Meghan was very impressive, very confident, and very capable, according to a source."

Markle hit the ground running when she joined the firm. But less than two years after marrying into the royal family, Prince Harry and Markle decided to step back from their royal duties.

In an interview with Fox News Digital, Nicholl explained that marrying into the royal family was "really tough." She credited Prince William and Middleton's long engagement for helping the Duchess of Cambridge thrive in the firm.

Meanwhile, award-winning British journalist Duncan Larcombe, a former royal editor at The Sun, speculated that Prince Harry didn't give Markle the right expectations when she joined the royal family.

"I feel desperately sorry for Meghan," Larcombe told Fox News Digital. "Harry clearly never really wanted to admit to her what was actually going to be involved with the royal family."