Spielberg films are renowned for the levels of secrecy and security during filming, and War Horse was no exception: filming took place under the codename Dartmoor.
The filming period took 'about 64 days' in total.
Filming of War Horse began with the cavalry scenes being filmed at Stratfield Saye House in north Hampshire, the estate of the Duke of Wellington, where incidentally Wellington's war horse Copenhagen is buried. Here a cavalry charge involving 130 extras was filmed.
Filming on location on Dartmoor, Devon started in August 2010.
Initially, Spielberg was only going to have four or five days' worth of second unitmaterial shot in Devon, but after Kathleen Kennedy sent him photographs of the various locations she had scouted, he decided to cut other elements of the story to enable more filming to take place in countryside that Kennedy described as "so extraordinarily beautiful and absolutely perfect for the story"
Dartmoor locations included the small villages of Meavy and Sheepstor, Burrator Reservoir, Bonehill Rocks and surrounding area near Widecombe-in-the-Moor, Ringmoor Down, Combestone Tor and surrounding area, Haytor, Hexworthy Bridge and Cadover Bridge/Brisworthy. Ditsworthy Warren House, an isolated Grade II listed building near Sheepstor on Dartmoor served as the Narracott family's farmhouse, and many scenes were filmed in the surrounding area.
On 11 September 2010, the annual Dartmoor Yomp was re-routed to allow filming to continue undisturbed. Spielberg praised the Dartmoor countryside's beauty: "I have never before, in my long and eclectic career, been gifted with such an abundance of natural beauty as I experienced filming War Horse on Dartmoor... And, with two-and-a-half weeks of extensive coverage of landscapes and skies, I hardly scratched the surface of the visual opportunities that were offered to me." Spielberg felt that the landscape was very much a character in the film