Royal Bombshell: Disturbing Secret The Queen Took to Her Grave Revealed 3 Years After Monarch's Death — 'Knowing What Happened Tore Elizabeth Up Inside'

A bombshell secret has rocked the royal family three years after the death of longtime monarch Queen Elizabeth II on September 9, 2022, RadarOnline.com can reveal.

Long before Prince Harry was branded the Royal Rebel, Elizabeth's younger sister Princess Margaret caused trouble and ruffled feathers with her epic palace bashes, rumored affairs, and insatiable thirst for whiskey.

Margaret was the opposite of the demure monarch and at times could be quite cruel, even to her friends. Royal biographer Meryle Seacrest claimed in her new book, Princess Margaret and the Curse, her behavior was due to suffering from an "invisible disability" brought on by fetal alcohol syndrome.

A palace insider claimed when Elizabeth died at age 96, she "must have suspected the truth about Margaret's condition at some point."

She added: "Some courtiers even claim the queen confessed the dark family secret on her deathbed. Knowing what happened had to tear Elizabeth up inside, because her sister suffered so much.

"The book is rocking the royal family."

According to the Mayo Clinic, fetal alcohol syndrome is "a condition in a child that results from alcohol exposure during the mother's pregnancy" and can lead to "disabilities related to behavior, learning and thinking, and physical development."

Fetal alcohol syndrome was not identified until 1973, so the Queen Mother likely would have been unaware of the dangers of drinking while pregnant with Margaret, though she did abstain from drinking while carrying Elizabeth. She wrote to her husband, King George VI, that the "sight of wine simply turns me up!"

While Margaret did not suffer the physical signs of fetal alcohol syndrome, she was plagued by mood wings, stunted growth, learning disabilities, migraines, and addiction issues.

There were other signs too. According to Seacrest, family and nurses thought of Margaret as "naughty, mischievous and provocative" risk-taker, who once purposefully sank her own boat during a rowing lesson.

Margaret earned a reputation as an adult for her unfiltered mouth. She once told Grace Kelly she didn't "look like a movie star," called Elizabeth Taylor's engagement ring "vulgar," and told British model Twiggy her nickname was "unfortunate."

Another disturbing character trait highlighted was Margaret's lack of concern for her physical safety.

Once, she accidentally set her hair on fire during Christmas at Sandringham and was known for smoking up to 60 cigarettes a day, even after a portion of her lung had been removed.

But Margaret embraced her black sheep label. She once said: "When there are two sisters – and one is the queen, who must be the source of all honor and all that is good – the other must be the focus of the most creative malice, the evil sister."

Despite their vastly different roles, Margaret always supported Elizabeth, and the sisters shared a fiercely loyal bond.