TORONTO -- The apparently fractured relationship between royal brothers Prince William and Prince Harry may have been baked into their bloodline, according to a prominent British biographer.

In an interview set to air Nov. 21 on CTV’s Pop Life, Robert Lacey, author of “Battle of Brothers,” noted a long history of sibling rivalry in the Royal Family.

Some have suggested that “the heir and the spare” way of thinking -- that William was groomed to be king and Harry played second fiddle -- affected how they were raised and even Harry’s eventual divergence from the family. Similarly strained were the relationships between Queen Elizabeth and Princess Margaret, and between Prince Andrew and Prince Charles.

“Harry is in fact the third spare that this has happened to. All the spares in the Queen’s reign have come to grief,” said Lacey. “They start off as costars.”

Lacey said the “rather cruel stereotyping” of birth order in the Royal Family w​as a “major factor” in the brothers’ relationship, the consequences of which may have played a role in apparent feuds in recent years, namely Harry pulling away from royal duties to move to North America with Meghan, the Duchess of Sussex. In a 2019 interview before the major announcement that he would step back, Prince Harry addressed rumours of a feud between the brothers, saying:

“We’ll always be brothers. We’re certainly on different paths at the moment, but I will always be there for him and, as I know, he will always be there for me.” William never publicly reciprocated the olive branch, said Lacey.

For royal watchers like Lacey, who is a historical consultant to the Netflix series The Crown, the forking of the brothers’ lives began at a young age and was forged by the dissolution of their parents’ marriage and mother’s death, a timeline detailed in Lacey’s book, which was published in October. Lacey recounted a scene in which a four-year-old Harry told his nanny that he didn’t need to “behave, because he wasn’t going to be king like his then-six-year-old brother William, who at that time was already becoming more serious, preparing for his royal destiny.

“I would go so far as to say that the knowledge he was going to be king kept William going through all the trials and tribulations of the breakdown of his parents' marriage, not to mention the death of his mother,” said Lacey.

“For Harry, he took a different lesson from what had gone wrong. Love is what matters to him. And so we have this classic clash that goes right back to 1936 in the British monarchy -- a clash between love and duty. And just as in '36, the abdication of Edward VIII, duty won, love was exiled. The same has happened now.”

Earlier this year, Harry and Meghan moved to Canada and later California, where they struck a content deal with Netflix and where they reportedly plan to spend most of their time. As in other times throughout the Royal Family’s history, the turbulence of recent has led many to wonder: will the monarchy survive this? Lacey is certain it will, though it’s unclear how the public will respond to an eventual King Charles III and a Queen Camilla. 

“The Royal Family will come back,” he said. “Canadians must speak for themselves, but I'm sure so long as Elizabeth remains Queen, people’s loyalty to the monarchy will remain.”