"Finding Freedom," a biography on Prince Harry and Meghan Markle releasing on Tuesday, has claimed that the prince's reconciliation with his elder brother Prince William is crucial for the existence of British monarchy.

The tell-all biography titled "Finding Freedom: Harry, Meghan and the Making of a Modern Royal Family" has explored in detail the differences between Prince William and Prince Harry. In the book, written by Carolyn Durand and Omid Scobie and published by Harper Collins, palace insiders have been quoted saying that the future of the monarchy in the United Kingdom depends on the royal siblings mending their rift, reports Page Six.

"We cannot have them at war," a palace courtier said about the two children of Prince Charles and late Princess Diana.

According to the book, the Duke of Sussex distanced himself from his older brother to protect his wife, Meghan, while William has not yet been able to recover from Harry and Meghan's decision to quit as senior members of the British royal family and relocate to the US. Palace staff was reportedly so worried about the feud between the two brothers following Harry's marriage to the former American actress that it was the hot topic of discussion at a summit in the spring of 2019.

"We need to design a system to protect the monarchy full stop," a source had said at a palace retreat, before the Duke and the Duchess of Sussex had moved from their Nottingham cottage residence on Kensington Palace grounds to Frogmore Cottage in Windsor, thus going far from William and Kate Middleton's apartment 1A at Kensington Palace.

"The future of this monarchy relies solely on the four people currently in Kensington Palace. The public popularity only lies with them," the insider said, noting that when Charles becomes king, the only way the monarchy can survive is if his two sons and two daughters-in-laws are not at "war."

The British royals
Rumours that all was not well with the Sussexes surfaced in October when Harry, sixth in line to the throne, admitted that he and William were "on different paths" and had good and bad days in their relationship. Photo: AFP / Paul ELLIS

Meanwhile, a friend of Harry's admitted that the healing of family wounds will take time now as the royal has moved to Los Angeles with wife Meghan and son Archie and is focusing all his time on their new charitable venture, Archewell.