Audrey Hepburn's Secret Shame About Her Mother's Nazi Sympathies: New Book Reveals

Onscreen, Audrey Hepburn‘s life often seemed like a fairytale, but the actress’ real-life story was shadowed by lasting trauma from her experiences during World War II.

It was something she rarely spoke of in detail.

Part of the trauma was rooted in her mother Dutch Baroness Ella van Heemstra’s early Nazi sympathies, which are detailed in a new biography Dutch Girl by Robert Matzen, excerpted by PEOPLE in this week’s issue.

Says Matzen: Hepburn “feared Ella’s Nazi past would kill her career, but still, they remained close.”

Ella had met Adolf Hitler in 1935 and wrote he was a “most charming personality” in a British Fascist newspaper. She kept a framed photograph of herself taken at Hitler’s Munich headquarters from the day.

After Germany invaded Holland, she saw maintaining cordial relations with German Nazi officers as the best way to keep her family safe.

For a time she even dated a Nazi officer.

Hepburn didn’t share in her mother’s views. The Breakfast at Tiffany’s actress barely survived Germany’s five-year occupation of Holland, and she risked her life for the Dutch Resistance — ferrying messages to British and American fliers who’d been shot down over Holland and delivering the Resistance newspaper to Dutch loyalists.

In addition, her entire family hid a British paratrooper in their cellar after the devastating Battle of Arnhem.

Hepburn’s younger son, Luca Dotti, tells PEOPLE, “There were times reading this book that I was crying.”

“I imagine how brave my mother was and how easily she could have died,” he says. “You can feel her trauma but also her strength.”

For more about Audrey Hepburn, pick up the latest issue of PEOPLE, on newsstands Friday.

Through secret police files, classified archives and interviews with Dutch survivors who knew Audrey and her family, Matzen reveals how Ella, like some aristocrats in the 1930s, had fallen for Hitler’s nationalism and promises of economic prosperity.

Yet that all changed when she experienced the brutality of the Nazi regime.

“After the execution of her brother in law, Otto van Limburg Stirum, who did not support the Nazi regime, and after many of her Jewish friends had been sent away to concentration camps, Ella turned her sympathies to the Dutch Resistance,” says Matzen.

Hepburn was never able to accept her mother’s early affiliation with the Nazis, Matzen writes. It became a secret she guarded her entire life.

Hepburn pursued acting after the war and moved to London where she was joined by her mother after a Dutch investigation into her pro-Nazi activities concluded and found Ella to be “politically unreliable” but not guilty of crimes.

Hepburn never confronted her mother about her early support of Hitler and carried the weight of it for many years.

Still, the two shared a bond after surviving the war, and she cared for her mother in her later years at her home in Switzerland.

Hepburn, who died in 1993 at age 63 from abdominal cancer, spent the last four years of her life as an ambassador for UNICEF. Even more than her beloved films, she found in her mission to call attention to the suffering of the world’s children, her true calling.