Princess Eugenie surprises fans with fact about mum Sarah Ferguson in social media post: 'I had no idea!'

The Duchess of York is well known as a passionate philanthropist, and of course, former member of the royal family.

But her daughter, Princess Eugenie, has just revealed a surprising fact about her mother that you may well not have known.

In a recent Instagram post, the Princess paid tribute to one of her royal ancestors, Queen Victoria.

And towards the end of the caption, she revealed that her mother, Sarah Ferguson, actually worked on a film about the late royal back in 2009.

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Eugenie revealed the interesting fact that Fergie actually produced The Young Victoria, starring Emily Blunt and Rupert Friend, of whom the Princess also shared a picture.

She wrote, 'The second [picture] is of Emily Blunt and Rupert Friend, who played Victoria and Albert in The Young Victoria (2009) - a film produced by @sarahferguson15'.

Princess Eugenie's followers were clearly floored by the revelation, with many admitting that they had no idea of her mum's involvement in the movie.

One fan commented, 'I had no idea your wonderful mother produced this film. It’s one of my very favorites. She’s very gifted!'

While another said, 'Oh I didn’t know your mum produced it! Very well done.', while a third wrote, 'OMG, your mom produced it 😱 I really love that movie'

And a fourth also confessed, 'I had no idea that your mum did that but it’s one of my favs.'

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Reportedly, it was actually Fergie's idea to create a movie based on the early years of Queen Victoria's life. The Duchess had been intrigued by her since marrying into the royal family herself, and even wrote two books based on her life.

Later on, renowned director Martin Scorsese was brought onto the project, to make The Young Victoria happen.

Talking to Reuters about her involvement in the film, Sarah revealed that she related most to the character of Prince Albert, and marrying into the royal family.

She confessed, "Prince Albert, because I know what it’s like to be a guest.

"It is very difficult when you are not born in to it, to fit in to a life that you cannot logically understand. (Those born to it) are born to duty and to be selfless to the grave."