Prince William and Prince Harry have a new book, titled Battle of Brothers: William and Harry, which will explore the rift the two have. Aside from delving into the royal brothers' relationship, it will also feature the role of their wives, Kate Middleton and Meghan Markle, into their ups and downs, and the reason behind it. 

Royal historian Robert Lacey admitted he was "moved to tears" when he researched what the novel entailed. In a press release, he also revealed he was "astonished and elated" about the new details and insights he discovered in this new story about the siblings' conflict.

He went on to say, via Us Weekly, that it is both "enthralling and painful" to trace the family drama. He even described the rift between the two princes to rank alongside the abdication of King Edward VIII due to its impact on the monarchy and how it set off.

Lacey also praised Queen Elizabeth II for handling the crisis excellently, calmly and stoically. Prince William and Prince Harry also remained honest and decent within the system, as well as Kate Middleton and Meghan Markle.

Allegedly, the rift between the two dukes was partly due to their personalities, but things got worse by how the monarchy works. They used to be close and inseparable. Now, they were separated by distance.

Although it seemed to be a usual sight to see conflicts between the heir and spare, Lacey claimed nothing was so profound as Prince William and Prince Harry's rift. Although it seemed to be unclear if they could be as close as they were once, Queen Elizabeth might play a crucial role in mending their relationship.

Meanwhile, royal aides fear that there will be a new so-called "Megxit war" if Prince Harry and Meghan Markle's new book, Finding Freedom, will blame Prince William for their rift and departure from the monarchy, The Sun noted. They are quite worried that the Duke of Cambridge may be "painted" as the bad guy, portraying him as "unsympathetic, unfeeling, and unsupportive" toward his younger brother and wife.

An alleged source revealed that the royal aides were talking about the book and how it might only show Prince Harry and Meghan Markle's side of the rift. Although it was not an official biography, it might be unfair for Prince William if their fears would happen.

Prince Harry and Meghan Markle's Finding Freedom will be out in August. The Duke of Sussex and Prince William's Battle of Brothers, alternatively, is set to be released in October.