The latest ITV crime drama to take over our evenings is Joan and stars Sophie Turner as the notorious jewel thief Joan Hannington, following her journey from mother and housewife to becoming one of the biggest figures in London's criminal underworld in the 1980s, known as the "Godmother" .

The six-part drama kicked off last night (29th September), and saw Sophie as Joan who runs away from her gangster abusive partner Gary, and puts their young daughter Kelly in care to keep her safe. What follows is the start of Joan's first steps into criminal activity, after she steals diamonds by swallowing them and starts a working relationship with thief and antique dealer Boisie (Frank Dillane).

So how much of this series is based on a true story? And what has been embellished for TV? Well here's what you need to know.

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ITV

Is Joan based on a true story?

Yes! The ITV six-part series is based on Joan Hannington's 2002 memoir I Am What I Am: The True Story of Britain's Most Notorious Jewel Thief.

The series screenwriter Anna Symon met with Hannington before writing the series in order to get permission to tell her story, and the pair worked together on crafting the story for the screen.

"I took a lot of anecdotes from the book, but I really hope – and I think I did from Joan’s reaction when she saw it – [we] capture the emotional truth of her as a character, and I could then use that truth and that spirit of Joan but turn it into what I hope is a compelling, entertaining television series," Anna said.

What is Joan's real story?

The real Joan Hannington was born in 1957 as the youngest of six children in West London. She left home at 13 years old and later married the convicted armed robber Ray Pavey, whom the character of Gary is based on.

The pair's marriage broke down and just like in the series Joan put their daughter Debbie into care. Similarly to the series Joan then met Boisie Hannington, who was 17 years her senior and taught her everything she knew about thieving.

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ITV

They worked together and ended up getting married when she was 24 years old. Joan was then arrested and sentenced to 30 months in jail for using a stolen chequebook.

After being released from prison she got a new job at a different jewellery store without disclosing her criminal record. She continued stealing jewels, and in Joan's memoir she revealed during her time there she swallowed around 20 diamond rings and swapped over a half a million pounds worth of diamond bracelets for fakes.

The couple would stash their millions in a bank vault and spend it on designer cars and clothes, and go on luxury holidays, flying first class.

During this time Joan and Boisie had a son called Benny. Boisie died in a fire in 1987 after planning an arson attack on their house in order to claim an insurance payout.

Did Joan really swallow diamonds?

Yep! One of the most surprising parts of the first episode was to see Joan swallow three little diamonds from the safe in the jewellery shop. And it turns out this was her precise method of stealing jewels in real life.

Despite there not being security footage or computerised methods to track diamonds as there are now, Joan still went with this foolproof method to secure her jewellery.

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ITV

The real Joan revealed she used to practice generating salvia in her mouth so she could sallow more rings.

"Best bank in the world is your tummy. Best safety-deposit box invented," she wrote in her memoir. She would bury the jewels in a biscuit tin in her garden in her council flat in Islington.

She also used a number of elaborate disguises in order to help secure more jewels.

Joan continues on ITV