Prince William's "Protective Instincts" for Prince Harry Kicked in While Witnessing the "Slow Death" of Charles and Diana's Marriage, Per Royal Expert

Prince Harry and Prince William sit together on the steps of Highgrove House wearing army uniforms on July 18, 1986.

Princess Diana and King Charles announced their separation in 1992, before finalizing their divorce in 1996. At the time, their two sons—Prince William and Prince Harry—were still young, and likely experienced a difficult transition when their parents split up. According to a new royal biography, Prince William even developed some "protective instincts" while witnessing his parents ending their marriage.

In the new royal biography, William and Catherine: The Monarchy's New Era: The Inside Story, royal expert Russell Myers revealed that Princess Diana tried her best to prepare Harry and William for their futures.

"Diana smothered the boys with affection, equipping them with her sense of humor, her appetite for fun, and her appreciation for the privilege she enjoyed—the qualities that she became renowned for throughout the world," Myers explained. "Diana believed this sense of normalness, no matter how small the gestures, would equip these boys for what lay ahead when they became central figures within the institution."

"Diana believed this sense of normalness...would equip these boys for what lay ahead." (Image credit: Getty Images)

Russell Myers

'William and Catherine'

However, the tumultuous nature of Charles and Diana's marriage reportedly influenced Prince William and Prince Harry in a major way.

"The brothers already shared a deep bond, with William forging the protective instincts he would display for decades," Myers wrote. "As an understanding of the slow death of their parents's relationship crept up on them, William made sure he was always accessible to Harry."

After moving to the boarding school Ludgrove School in Berkshire, England, "William would summon that same maturity to protect his younger brother from the realization that, after years of speculation, their parents's marriage was all but over," Myers shared.

"Both Charles and Diana attempted to shield their children from the furious rows." (Image credit: Tim Graham Photo Library via Getty Images)

According to Myers, "Despite the acrimoniousness of the breakdown, both Charles and Diana attempted to shield their children from the furious rows that were tearing them apart, often with little success."

In an exceedingly difficult situation, Prince William reportedly wanted to ensure his little brother was safe, which led to him developing his keen "protective instincts."