September 24 2010: Castle Combe is a small, picture-perfect hamlet in Wiltshire where visitors have tea and cakes and there is a hoo-ha if someone puts up a satellite dish. It is sweet, conservative and sleepy. But it also has a whiff of Hollywood glamour about it. In 1966 Dr Dolittle, starring Rex Harrison, was shot here (and ever since the village power lines and telephone cables have been buried underground).  And now Hollywood has returned. Steven Spielberg is issuing instructions through a loudhailer, looking cold in a baseball hat and grey scarf. War Horse is being shot entirely in Britain, even the French battle scenes (at Wisley Airfield, Surrey). Spielberg last filmed here in 1989 (Empire of the Sun) and 31 days of shooting in the United States and New Zealand for The Adventures of Tintin has not prepared him for the realities of a late English summer.  'They had the same crappy weather as we've had,' he says of the Dolittle production, 'but it's so charming here. It feels like someone built the town for a film. It looks like it's laid out for a 2:35 aspect ratio [the format of a film for cinema viewing].'  Castle Combe's high street is filled with ducks and theatrical mud and assistants touching up make-up in front of mullioned windows (no double-glazing here). Spielberg is shooting the scene where the men of the village are being waved off to war, and 200 or so extras are marching through the streets carrying suitcases and singing the haunting refrain of 'Only remembered for what we have done'.  But choreographing the phalanx is not easy. 'Can they be slower?' Spielberg shouts. 'They're racing through.' There is another take and then a smile and a thumbs-up to the crew. 'It's wonderful to see that after all these years there is still a real sense of joy when it goes well,' Richard Curtis, who is here to meet Spielberg, observes. 'Isn't this place impossibly beautiful?' he continues. 'I keep tapping things to check they're real.'  In 2004 Tom Morris (now the artistic director of Bristol Old Vic) was appointed an associate director at the National Theatre. His remit was to refresh the audience and encourage children. As he cast around for suitable projects, his mother suggested War Horse. On the face of it, no material could be less promising. Morpurgo's novel is told entirely from the point of view of a horse – Joey. But Morris's genius was to collaborate with the Handspring Puppet Company from South Africa, whose work he had come to know when he was the director of Battersea Arts Centre in London.  In October 2007 Joey burst on to the Olivier stage and reared into neighing, breathing life as a cane and georgette puppet. After two sold-out runs, it moved to the New London Theatre in the West End in 2009.  In the audience that summer was Kathleen Kennedy, a producer and Spielberg's longtime collaborator, who was in London on holiday with her husband and daughters. 'I was pretty staggered by it,' she recalls. She knew enough about Spielberg, having worked with him since ET (1982), to know that what War Horse represents – 'a very simple premise set against very large emotional ideas' – is a recurring Spielberg theme. A week or so later, Spielberg flew to London with his wife, the actress Kate Capshaw, specifically to see the play. 'I loved it, adored it,' he says. 'I was just a wreck. When Joey made that tremendous transformation on stage from colt to teenager – that was it for me. I didn't have a dry eye for the rest of the show.'  War is a Spielberg speciality: 1941, Raiders of the Lost Ark, Schindler's List, Empire of the Sun, Indiana Jones and the Last Crusade, Saving Private Ryan; but always the Second World War. 'The First World War isn't a subject that is often spoken about through story, television or motion picture in our country,' he says.  The other appeal was horses. Spielberg owns a ranch in Los Angeles where his wife rides dressage and one of his daughters (he has seven children from two marriages) is 'an accomplished hunter-jumper'. And, he says, he was not prepared for the statistics that emerged from the Imperial War Museum: more than four million horses perished during the Great War. 'Not all in close combat; there were a lot of deaths just through malnutrition and mistreatment.'  Ultimately, however, it was the story that drew him in. Joey is a horse that doesn't take sides. He moves from the English to the Germans to the French. 'What was irresistible for me is how Joey linked disparate characters together and the lengths to which Albert went to find him,' he has said.  To his surprise, he discovered that the book's film rights had not been optioned. 'I'd tried to make a film of it 20-odd years ago with a producer called Simon Channing Williams [Mike Leigh's late producer],' Morpurgo explains, 'but he didn't have the contacts and he also made the great error of asking me to write the screenplay, and it was going to be too expensive. Everyone who looked at it thought, horses, First World War… no.'  In 2009 Kathleen Kennedy flew to England where she had breakfast with Morpurgo. The script lay for a while in the hands of Lee Hall (best known as the writer of Billy Elliot) who was then replaced by Richard Curtis, who brought the screenplay closer to the book, but miles away from the comedy of Notting Hill, Four Weddings and a Funeral and Love Actually.  'It was rather a release not to think, "Are there any jokes in it?" ' Curtis says. 'The real job was the book's very peculiar structure.' Joey gets passed like a baton among leading characters: from Albert to Capt Nicholls, who buys him as his mount in the artillery; devoted Trooper Warren; little Emilie, an orphan, who lives with her grandfather; Friedrich, 'a kind and gentle' German soldier; and so on. It is, in effect, a series of miniature plots.  War Horse the film zeroes in on a boy's love for his horse. Albert (Jeremy Irvine) is a lonely boy who lives in a very isolated part of Devon with his father (Peter Mullan) who has a 'gimpy' leg and a drink problem, and his put-upon mother (Emily Watson). Spielberg is known for creating films where you need a box of tissues as well as a bucket of popcorn, and War Horse combines an idealised view of Albert and Joey's life in Devon – green pastures, rambling roses, there's even a bucolic shot of Albert up a tree calling Joey with his special whistle – with harsh scenes of a burnt-out no man's land. Not that the shots of war, Spielberg stresses, are as visceral as those in Saving Private Ryan. 'We're hoping for a family audience here.'  The main problem was how to get inside the head of a horse. As in the novel, Spielberg wanted the film to be told from the horse's point of view. The idea of attempting this with real horses, let alone the thought of them getting entangled with barbed wire and looking like prisoners of war after being in the trenches, was surely daunting?  'I've spent my whole career working with animals of all kinds, but I've never had a movie so animal-centric and it is difficult,' he admits. Particularly as he didn't want the audience to be fobbed off with virtual horses. 'When you have so many live shots of animals and you suddenly introduce CGI [computer-generated imagery] the audience would intuit that something was artificial,' he argues. 'But we have a couple of tricks to accomplish stunts that don't involve a live animal.'  The film, even by Spielberg's standards, involved a colossal number of people: 5,800 extras and sometimes up to 280 horses in a scene. The equine unit encompassed grooms, trainers, drivers to haul the horses and the feed, people to set up portable barns, vets, and teams of up to 26 doing the horses' make-up, all overseen by a representative from the American Humane Association. It sounds more like a travelling rodeo, or an equine rock festival, than an ordinary film department.  'Everyone laughs because they're thinking of mascara on horses,' says Ali Bannister, the equine artistic adviser, although she admits that each horse had a make-up bag, filled with grooming products. She says it was her job to paint Joey's signature white cross on his forehead and add four white socks; futhermore to do it on all the Joeys, because the part was played by 11 different horses.  'I was amazed at some of the things the horses did for their trainers,' she goes on. 'You would see one of the horses looking really aggressive but the moment the trainer stopped giving him the signal he would just plop to the floor and nibble a bit of grass. I've never in my life been around a horse that looked so angry, and then have it just instantly disappear. Normally you can teach an animal to do the moves but this particular one would do it with such expression.'  Back on set, Jeremy Irvine (Albert) is in make-up. Irvine's first concrete task was not only to learn how to ride a horse but also to act in a film. His previous total experience was being Romeo in a play at Bedford Modern School, Bedfordshire, and a tree in the chorus of the Royal Shakespeare Company. 'I was literally playing a tree, no lines, and at the time I thought that was probably as good as it was going to get,' he says. 'And then to go from that to suddenly having lines and being the lead in a Steven Spielberg movie is not real to me. I still need to let it sink in.'  'I looked for months and months [to cast Albert],' Spielberg has said. 'I was running out of hope, then Jeremy Irvine came in towards the last third of the casting process.'  Irvine plays Albert as an innocent. 'Joey is like Albert's brother,' he says. 'It has to be that kind of relationship, the stakes have to be that high for him to go off to the First World War to get him back.'  Tom Hiddleston (Capt Nicholls) is more experienced (Loki in Thor; F Scott Fitzgerald in Woody Allen's Midnight in Paris; Freddie Page in The Deep Blue Sea) but War Horse required him to lead a squadron charge across a battlefield where 120 horses and men gallop towards machine guns. To prepare he spent five weeks doing intensive training with a horse instructor in Rickmansworth, Hertfordshire. 'Just step by step, learning to trot, canter, ride one-handed, with a sword in my hand, and then do it in formation with the other actors, Benedict Cumberbatch [Major Stewart] and Patrick Kennedy [Lieut Waverly].'  The battle was shot at Stratfield Saye House in north Hampshire, the estate of the Duke of Wellington. 'It was one of the most amazing days of my life,' Hiddleston recalls. 'One hundred and 20 horses waiting in line in a phalanx of military formation, and everything about the context was real except for the bullets.'  This isn't strictly true, as in order to create the desired effect of men and horses streaming like ghosts from a field of reeds, plants were imported from another part of the country. 'There was a marsh in the south of London still in bloom,' Rick Carter, the production designer, has said. 'We went there and paid a farmer to cut his whole field down, then we put the reeds in styrofoam.'  'I'll never forget the feeling of having to call the orders,' continues Hiddleston, who looks impeccable as Nicholls, a firm leader in a beautifully tailored uniform, an emblem of a gentler, more respectful way of being. He takes a deep breath. ' "Forward to walk. Walk. March. Forward to canter. Canter. March." And then raising my sword and screaming "Charge!" and hearing the sound of 480 hooves around me, galloping at 40 miles an hour across 400 yards of open plain.' He stops, silent for a while. 'Captain Nicholls is a soldier poet,' he says, 'the kind whose like was never seen again.'  'War Horse' is out on January 13
The transformation of War Horse from an unnoticed children's book to an   award-winning play was a coup. Now Steven Spielberg is bringing the drama to   the big screen