Prince William has been accused of being "ruthless" to Prince Harry and Meghan Markle. 

Following their bombshell decision to step down as senior members of the Firm, the Sussexes faced cruel treatment from Queen Elizabeth II. Now, the Duke of Cambridge is rpeortedly following suit. 

According to Robert Lacy, the author of the recently released "Battle of Brothers" and historian for "The Crown," the future king of England inherited Queen Elizabeth II's attitude of duty before family. 

In his interview with Vanity Fair, the royal expert recalled how the 94-year-old monarch showed her ruthlessness toward the Duke and Duchess of Sussex when she barred the couple from using the word royal for their future endeavors. 

"At the end of the day, we saw a ruthlessness from the Queen over her absolute refusal to allow the Sussexes to use the word royal for their new branding, and we're seeing the same ruthlessness in William," Lacy explained.

To recall, Her Majesty stripped the duo of their HRH titles and blocked them from using "Sussex Royal" for their upcoming projects outside the royal family.

At the time, the Daily Mail cited that the couple agreed to the Queen and the palace officials' condition to ditch the term "royal" for their branding following Megxit. 

"The Mail understands that, amid what has been described as a 'complex' situation, the 'fine detail' is still being thrashed out," the publication's royal correspondent Rebecca English wrote. "However, it is understood the couple has accepted that, as part of their new working arrangements, they will not be able to use the Sussex Royal name as they had hoped."

Prince William Being Overprotective of Prince Harry?

Lacey also spoke about the Duke of Cambridge's dedication to his duty that went beyond his relationship to Prince Harry that later on strained their bond as brothers. 

In his bombshell book, the royal author claimed that Prince William was concerned about his younger brother's fast-paced romance with the former "Suits" star. 

This came after Prince Harry expressed his desire to pop the question only after meeting the Los Angeles-born actress in 2016. 

Apparently, the future king was "worried" over harry's decision to marry Meghan and thought that he was "going too fast."

"This all seems to be moving rather quickly,' William was said to have remarked to Harry doubtfully on the testimony of more than one friend. 'Are you sure?'" the book stated. "William couldn't understand how Harry could contemplate marrying this still unknown and untested quantity less than two years after their first meeting."

The royal expert then pointed out the difference between the two and recalled how the father of three waited almost a decade to marry Kate Middleton. 

"If 'Waity William' had taken nearly a decade to test out and approve his life partner, surely his younger brother could ponder his options for just a year or so more?"

Lacey then added that because of his duty and the crown, "waity William" had to wait years before committing to a lifetime decision. 

READ MORE: 'Iron Man' Star Gets Honest About Cancer Diagnosis