AUDREY HEPBURN -- Pictured: (l-r) Mel Ferrer, Audrey Hepburn -- Photo by: NBCU Photo Bank
Credit: NBC/Getty Images

As one of America's style and movie icons, Audrey Hepburn's life has always been a subject of public curiosity. And now new details have emerged on the actress's secret wedding to Mel Ferrer thanks to a collection of handwritten letters set to auction at Bonhams later this month.

In one of them, Hepburn wrote to her lifelong friend, British actor Sir Felix Aylmer, that she wanted to keep her nuptials to Ferrer a "dark secret."

“How dearly we would love you to be with us on our wedding day. We will have the car take you up to our mountain peak, Friday, for a gathering in our chalet of our nearest and dearest! . . . Saturday will be the wedding . . . We want to keep it a dark secret in order to have it without the ‘press," she wrote.

Hepburn and Ferrer married on September 25, 1954 in Switzerland, and had one child together. Unfortunately, the couple divorced after 14 years in 1968.