Fiennes did not intend to play Charles Dickens himself at first. But if he had doubts, others did not. "I kept saying to him, 'You must play Dickens! You were born to do it!" recalls Tomalin.

"For me it was always going to be Ralph but it was just a process of persuading him," smiles Morgan.

"I was undecided for a long time," Fiennes admits. "Until after quite a few months of working on it, I felt, despite knowing it would be very difficult, that I couldn't resist playing him."

The Charles Dickens revealed in THE INVISIBLE WOMAN is a man possessed of ferocious energy. Not only does he juggle a young mistress with marriage and 10 children, but he successfully maintains a vigorous writing regime and roles as a journalist, actor, theatre director and social campaigner.

"In a funny way, that probably helped me because it was very Dickens to be organising people and doing everything," says Fiennes, of the enormity of the role he undertook as director and lead actor. "He was in control of everything."

As too was Fiennes. "It was Herculean what he did," says Gaby Tana. "Ralph was so prepared and so diligent. He immersed himself in the world of Dickens, which he didn't really know."

"He will not let anything go, he doesn't let you take the easy option," says Felicity Jones, the rising UK star who plays Ellen Ternan. "You'll be doing 15, 20 takes as he always wants to get something completely honest."

"He's like a laser, he won't let anything slip by," says Amanda Hale, who plays Nelly's middle sister Maria Ternan. "His emphasis is so much on performance, which is quite rare."

For Kristen Scott Thomas, who plays Nelly's mother, Mrs. Ternan, it was the third time she had worked with Fiennes following their famous on-screen love affair in The English Patient, for which they were both nominated for Oscars.. "I enjoyed being directed by Ralph as much as I enjoy acting with him," she says. "I'm in awe of what he's doing. He's keeping it all in the right place, with everything ticking over and at the same time he manages to remain one of the team as far as the actors are concerned."

Abi Morgan compares Fiennes' dynamism with that of Dickens'. "The tenderness, the sentimentality, the viciousness, and the brutality you can see in his work, they're embodied in the man. He can be co-writer, he can be director, he can be actor, and he can be production designer. He doesn't jump through those roles, he flows, and it flows through him."

For Fiennes, it was very important to convey Dickens' vitality, his love of life, and the sheer force of his charm. He points to the cheerful organised chaos of the rehearsal of The Frozen Deep, the first scene in which Dickens' appears, as crucial to this depiction. He describes Dickens as a man of "extraordinary imaginative power and range".

Like everyone working on the film, both Fiennes and Morgan were drawn to the complexity of Dickens, a revered man but one whose behaviour towards his wife was at times shocking.

"I knew people might not like him, that didn't worry me," says Fiennes. "He's a huge soul. And, as a man, deeply fallible. We can jump to judging him very quickly. Abi and I tried to show in simple scenes, the sense of a marriage, it's not people hating each other, but the spark has gone and there's a sort of a matter of fact-ness. I can't help thinking Dickens was looking for a real connection with a woman which he hadn't found with his wife. I think he saw Ellen Ternan and she was the ideal he had always written about. There she was, and that was that. He had to have her."

Morgan believes a creative chaos may have been at work, compelling the 45 year-old Dickens to fall in love with an 18 year-old actress. "Your 40s are interesting," she muses. "There is a compulsion to shake it up sometimes and there's a compulsion to take yourself as a person to different places because that informs your writing. That's what draws creative people to catastrophe and to drama sometimes because it's also where there energy starts to burn and where they get a lot of creative material from." Directing himself forced Fiennes to be unflinching when considering his performance.

"I have to look at myself, sit with my editor, choose the take. This is exposing and can be really tough" he says. "But editing any performance is an endless, wonderful, often infuriating puzzle. No one moment is ever the same. During the shoot I wait to catch the wave where it all becomes one thing. You can push, pull, cajole, tease, be brusque, be loving or be flattering or do nothing and just wait. It's probably best to just wait, which is hard on a film set."

One person who found Fiennes' multiple roles a slight challenge was the Oscar-winning make-up and hair designer Jenny Shircore, who had just worked with Fiennes on Mike Newell's Great Expectations in which he had starred as Magwitch. "To get him to sit still while I checked something was not as easy as it normally is because he was always thinking about the next shot and wanting to be there," she says.

"Ralph has got a real barometer for finding good talent," says Abi Morgan. "You have the incredible on-screen talent of Kristin, Felicity, Tom and Ralph himself, but you also have a huge ensemble of actors who aren't as well known who he is bringing to the fore. He's got a real eye."

The British film and theatre actress Felicity Jones was cast as Ellen Ternan even before Fiennes decided to play Dickens himself. Jones is one of the UK's hottest new acting talents following her award-winning role in Drake Doremus' Sundance 2011 hit Like Crazy and more recently Doremus' Breathe In, opposite Guy Pearce.

"I wanted someone who had great interior resources," says Fiennes of Jones. "Felicity's great gift is she's very intelligent and the camera reads a sense of other things happening inside of her."

In Jones' accomplished hands, Nelly is an astute, self-possessed young woman. "The older, Margate Nelly is someone who's got this secret she is sitting on and Felicity has an amazing ability to suggest that," says Fiennes. "And as the younger Nelly she has these moments when she laughs and is free, has a sense of humour, has a vulnerability. This is very much Felicity's creation."

Jones was captivated by the script and then by Tomalin's book. "I felt I had to understand who this woman was who'd almost been entirely eclipsed by history," the actress says of Ellen Ternan. "When Dickens meets Nelly he's confronted with someone who I felt wasn't particularly an open book. She's quite a closed character. There's something very unknowable about her and from the moment he first meets her he develops an obsession with her."

Two of Fiennes' close friends and colleagues also joined the cast: Scott Thomas, who Fiennes always had in mind for Mrs Ternan, and Tom Hollander, his great friend, who he cast as Dickens' great friend Wilkie Collins.

"He's uniquely inventive," says Fiennes of Hollander. "His insight into a part is always so delicate and sharp. He was also an amazing friend to me on set. Under pressure he was extraordinary in the support he gave to me."

The director worked with UK casting directors, Leo Davis and Lissy Holm of Just Casting to discover actors with which he wasn't familiar. "It forces you to define who a character is," says Fiennes of the casting stage. "But at the same time remain open to meeting different actors and suddenly realising, 'I hadn't thought of that but that person would be rather great'."

One of those was Joanna Scanlan who plays Catherine Dickens. She endowed the part of subdued and betrayed wife with a quiet dignity and intelligence. The delicacy she brought to her performance was crucial to the tone of the film.

"In Jo's performance," offers Morgan. "You feel Catherine's pain but you can see this is a woman who really loved Dickens, admired him and is caught by his plight. As much as she feels pain for herself she feels pain for his situation. That goes beyond anything I have written."

The camaraderie and vividness of the Victorian theatrical world that so appealed to Dickens was replicated on-set by the cinematic troupe put together by Fiennes. "It was always good fun on set," says Felicity Jones." Ralph was very good at creating an environment where people didn't feel threatened or intimidated. People wanted to do the best they could do."

The look of 19^th Century England was fastidiously researched and recreated for the film which shot for 10 weeks throughout the early summer of 2012. Fiennes felt strongly that the way into the period drama for the audience was to make it appear as real as possible. This belief encompassed the type of wallpaper and the weight of the dress fabric, as well as ensuring every letter burnt by Dickens in one scene is authentic and, folded as it would have been.

The crowd even shouted the actual names of the horses that raced at Doncaster on Derby Day in 1857. "I believe that if everything is very detailed, audiences feel the world," Fiennes explains.

One of the major reference points for this was William Powell Frith's famous painting "The Derby Day" of circa 1850. "We were going over it with a magnifying glass," says production designer Maria Djurkovic. "Somebody with a lobster here, a dog on a lead there. We have tried to be as accurate as we can without being slavish to it. It's a balance, that's what's fun about it."

Fiennes assembled an impressive group of UK heads of department. In addition to the award-winning Djurkovic, who picked up prizes from both the British Independent Film Awards and the European Film Academy for her work on the 2011 Cold War thriller Tinker Tailor Soldier Spy, Fiennes brought in Rob Hardy BSC as director of photography after seeing his work on James Marsh's 2012 film Shadow Dancer.

Fiennes had also worked with costume designer Michael O'Connor on The Duchess in 2008, for which O'Connor had won a BAFTA and an Oscar. Similarly, make-up and hair designer Jenny Shircore had earned an Oscar and a BAFTA for her work on Shekhar Kapur's Elizabeth in 1998 and had gone on to transform Fiennes into Magwitch in 2011 for Great Expectations. Locations work was overseen by the experienced Dutch-born location manager Michael Harm.

For the look of the film, Fiennes wanted a rather melancholy palette for the 1870s scenes that book-end the film. Set in Margate in Kent on England's south coast, the exteriors were shot just a few miles away on the commanding sweep of Camber Sands on which Hardy captured a low, wintery light. For the interiors of the Margate school where Nelly lived with her husband and child, Djurkovic translated the look into muted tones and a quiet, subdued aesthetic.

By contrast, the flashback scenes, where Nelly first meets Dickens 15 years before, represent a complete gear-change in colours and atmosphere. "The early stuff is her memory and her excitement at meeting this extraordinary man," explains Djurkovic.

Costume designer Michael O'Connor was able to use photography from the time, as well as the Frith painting and others by Dickens' contemporary Augustus Egg, to explore how the clothes of the time would have been constructed. "What Ralph was keen to do was to use the costumes more than once," says O'Connor. "There's nothing more unconvincing than people who keep changing all the time. In those days people did wear the same bonnet and re-trim it for a different occasion."

"As an actor, that's what you love," comments Perdita Weeks who plays Nelly's eldest sister, Maria Ternan. "It doesn't matter if the clothes are a bit smelly or you've spilt something down them. Otherwise you're walking around like a perfect Barbie and if feels completely removed from anything you're doing."

One of O'Connor's biggest challenges was working out what Nelly, the invisible woman, might have worn at two very distinct stages in her life. "The pictures show this arched kind of woman," he explains. "But they are later pictures and they are posed pictures. To find the woman who woke up in a cold cottage in the morning and went to the theatre and did a sort of average performance has been very difficult."

O'Connor worked with Felicity Jones to build Nelly's character subtly through costume. "You think it's just a costume but the detail, every layer is completely accurate as to how it would have been," says Jones of working with O'Connor. "With Michael O'Connor costumes, you just feel like a real person."

The transformative power of costumes came into play when dressing Kristin Scott Thomas as Mrs Ternan. "Kristin will look elegant in anything she puts on and the idea was to make her real, was to try and stop that happening. The temptation with Kristin is to make her dark and streamlined but in this period of lots of trim and fuss, you can add lots of accessories, trim and lace collars - things that that help go against what is natural for Kristin" says O'Connor.

As in any period drama, the hair and make-up work was very important. "Putting a centre parting in somebody's head and scraping it down either side of their face when they're used to having curly flouncy hair just immediately transforms you, as does putting on a girdle. It takes you into another period straight away," says Shircore.

"You also have to keep the actors in mind," she continues. "You have to keep their faces in mind, what suits them in the period, and also what their input is."

Most of the shoot took place on location in Kent, and in and around London with just two studio days filming the interior of the railway carriage. The exteriors of the derailment were staged in a siding of the Bluebell Railway, which operates heritage steam locomotives, in Sussex.

As in most of Dickens' novels, all the places described in Morgan's script existed. Location manager Michael Harm started by checking out the real addresses. If they no longer existed or were unsuitable for filming, Hale found matching houses and interiors. The biggest challenge was the contemporary fittings now adorning many of London's Georgian and Victorian houses as well as Dickens' Gads Hill home in Rochester, which had been turned into a school.

"It is an awful lot to do to get rid of all the modern fittings, the beautiful wall- to- wall carpets, the down-lighters, all the modern light switches," says Harm "So the search has to focus on where we have as little as possible for the art department and the construction department to do to make that work."

For example, although the exterior of Manchester's Free Trade Hall where The Frozen Deep rehearsal took place still looks authentic, the interior had been turned into a modern hotel. Harm and his team discovered the interior could be reconstituted at London's opulent Draper's Hall in the City of London.

"We managed to do an awful lot in a short time," he says. "Ralph Fiennes is a very visual director, so can describe very clearly what he's after. We were able to narrow down very quickly the ones that worked for him."

"He's incredibly visual," agrees Djurkovic. "He draws really well and does these amazing storyboards. Lots of directors do their own storyboards but Ralph's are really good!"

For his part, when he took on the project, first as director, then as director and star, Fiennes says he was cheerfully ignorant of most of Dickens' work, ignorant of Ellen Ternan, and hadn't read Claire Tomalin's book.

"I was more drawn to Russian writers – Dostoyevsky or Tolstoy", he explains. "At school I had somehow decided I wouldn't like Dickens. Maybe it was being overexposed to a recording of A Christmas Carol that we listened to as a family. I think I decided Dickens was too cosy, or comfy perhaps. I feel the opposite now."