And now, the 59-year-old has revealed details of a secret royal tragedy which hit the Windsor clan two centuries before she became part of 'The Firm'.
In a new TV documentary, Fergie travels to Germany to retrace the footsteps of the Queen's great-great-great-grandmother Princess Louise, the mother of Queen Victoria's husband Prince Albert, Hello! Magazine exclusively reports.
Princess Louise was separated from her two young sons and exiled to a remote German hamlet where she was forced to live out the remainder of her life without ever seeing her children again.
"She was discarded by her husband - Ernst I, the Duke of Saxe-Coburg-Saalfeld - and sent to St Wendel," the Duchess told Hello!.
"I wanted to know what Louise had done so terribly wrong that she could be taken from her children on...Albert's fifth birthday...put in a carriage and written out of history."
Fergie said the story resonated with her because of her own close bond with daughters Beatrice and Eugenie, who her and Prince Andrew are clearly devoted to.
Of her allegedly more than friendly relationship with her ex-husband, the Duchess of York said: "We work in unity, and Andrew and I are focused on being good parents together.
"We are bigger than friends. We learn from each other, support each other and understand its about communication, compromise and compassion."