Knightley, 39, has been acting since she was a child, receiving her first acting credit when she was just eight on TV show Screen One.

The British actor then took on the role of Elizabeth Swann in the Pirates Of The Caribbean franchise, appearing as the character in three of its films from 2003-2007, opposite Edward Scissorhand’s Johnny Depp, who played Captain Jack Sparrow, and Lord of the Ring’s Orlando Bloom, who played her character’s love interest, Will Turner.

However, fans on social media are only just discovering how old the actor was when she was shooting the first Pirates film, and have understandably been left with their jaws on the floor.

One fan took to X, writing: “Keira Knightley being like 17 when she filmed Pirates of the Caribbean shakes me to my core.”

Another said: “She looked 25 at 17 and stayed looking 25 to this very day.”

A third chimed in: “This really just impresses upon me how f**king talented she is as an actress. Like god damn girl you haven’t even been alive long enough to have this type of range.”

However, being catapulted to fame at such a young age isn’t all sunshine and rainbows, as the star has previously spoken out about her struggles with the attention as a young woman.

Speaking about the ‘many years of therapy’ that she underwent to help deal with her newfound success at the time, Knightley said that she was ‘taken down so publicly’ for her involvement in the franchise.

Speaking to The Times in a recent interview, she admitted that the experience was ‘making and breaking you at the same time’.

“I was seen as s**t because of them, and yet because they did so well I was given the opportunity to do the films that I ended up getting Oscar nominations for [Pride & Prejudice and The Imitation Game],” she recalled. “They were the most successful films I’ll ever be a part of and they were the reason that I was taken down publicly.

“So, they’re in a very confused place in my head.”

She said she was ‘taken down’ for her role in the franchise (Stephane Cardinale – Corbis/Corbis via Getty Images)

However, her experience following the three films left her wanting to avoid huge franchise titles for the rest of her career, labelling the hours ‘insane’.

“It’s years of your life, you have no control over where you’re filming, how long you’re filming, what you’re filming,” Knightley highlighted.

Speaking with The Telegraph in 2019, she said: “The fame that came with them I just couldn’t handle.

“So looking back, would I do anything different? No, I wouldn’t because I’m unbelievably lucky now, and my career is in a place where I really enjoy it, and I have a level of fame that’s much less intense.”

Knightley was also aware of being known as Elizabeth Swann and not much else, explaining to Harper’s Bazaar last year: “She [Elizabeth Swann] was the object of everybody’s lust.

“Not that she doesn’t have a lot of fight in her. But it was interesting coming from being really tomboyish to getting projected as quite the opposite. I felt very constrained. I felt very stuck.

“So the roles afterwards were about trying to break out of that.”I didn’t have a sense of how to articulate it. It very much felt like I was caged in a thing I didn’t understand.”