Prince William and Prince Harry were forced to reconcile and step out together on Saturday to greet a sea of mourners outside Windsor Castle for the sake of Queen Elizabeth II and King Charles III, a royal expert claimed.

Royal biographer Ingrid Seward told Mirror UK that Prince William and Prince Harry only put their differences aside out of respect for their late grandmother and father, who is now the new ruler of the British monarchy.

Seward stated, "When they jointly greeted the crowds outside Windsor Castle today, you knew they had put duty before themselves. It was just as Granny would have wanted, as she would have done. And it had to happen. People say grief brings people together, and I agree it does. When a person [whom] you both loved very much dies, you are united in grief and memories. For the sake of their grandmother and their father, the boys simply had to show unity."

The Majesty magazine editor-in-chief added, "As civilised people, they understood that the new King Charles III is relying on their support. And the last thing he needs at the start of his reign is to have press attention focused on the spat between his children. So, they will have thought, 'What can we do for Granny? Let's make this look good.'"

Most, if not all, royal fans are aware that Prince William, Kate Middleton, Prince Harry and Meghan Markle got reunited for a rare appearance together amid their ongoing feud after the shocking demise of Queen Elizabeth II. The Cambridge and Sussex couples were seen walking together side by side and talking amongst themselves as they read several tributes outside of Windsor Castle.

For a brief moment, Prince William and Prince Harry were seen acknowledging each other for a quick exchange as they stayed close to their wives. Each of the royals knelt down to read and check on the touching floral tributes the public gave in honour of the late Queen Elizabeth II.

Due to their long animosity, the reconciliation between Prince William, Kate Middleton, Prince Harry and Meghan Markle came as a surprise to many. To recall, the Duke and Duchess of Sussex announced their decision to step back from their senior royal roles in January 2020.

Prince Harry and Meghan Markle, in a CBS tell-all interview in March 2021, made shocking claims about the other members of the royal family. Since then, the "Fab Four" have not seen eye to eye – particularly Prince William and his only brother.

An unnamed source told In Touch that Prince Harry and the royal family are at odds following the demise of Queen Elizabeth. It claimed, "There's strife between Harry and the royal family for announcing the queen's passing before he arrived at Balmoral. Emotions are running high right now, and Harry was hoping his family would wait."

The anonymous informant added that the public would "be seeing them unite in public, but behind closed doors, there remains underlying tension. You would've thought Elizabeth's passing would have brought them closer as a family, but it's not the case. Hopefully, in time, they'll heal."

Both Prince William and Prince Harry have yet to comment on the claims that they were forced to reunite with respect to Queen Elizabeth and King Charles III. So, avid followers of the royal brothers should take all these unverified reports with a pinch of salt until everything is proven true and correct.

Prince William and Prince Harry
Prince William and Prince Harry Toby Melville - WPA Pool/Getty Images/IBTimes