War Horse is the story of the unbreakable bond between a young man and his horse. But it’s set during one of the darkest, most violent periods in human history: World War I. Joey the horse charges in battle, pulls cannons up a muddy hill and even finds himself lost in the infamously dangerous trenches of no-man’s-land. Real horses performed nearly every single stunt in the movie — except for the dangerous scenes, like the ones in which Joey ensnares himself in barbed wire or falls into a trench, which had to be fudged with the help of CGI. TIME talked to the film’s head horse trainer, Bobby Lovgren, about his work on War Horse, why young foals make the most difficult subjects to train and how he persuaded a horse to jump over a tank.
Horses are animals of flight — they scare so easily. Before you start training, how do you know whether or not a horse will be good for a movie?
We pick seasoned show horses or horses that have been exposed to crowds before; horses that have been in parades make good subjects. Any jumping or rodeo experience will give horses some exposure too, so that when we train them they aren’t starting from scratch. For a movie like War Horse, where we have to train very young foals and 2-year-olds that haven’t been anywhere, that’s where my knowledge of horsemanship comes in.
(MORE: Read TIME’s War Horse review)
The film is set during World War I. How do you get horses comfortable with gunshot and cannon sounds?
We’ll do something like make a loud noise in the distance and then slowly bring it closer and closer. We’ll submit them to smoke screens, popping sounds — basically try to show them a lot of different things and take them to as many locations as we can before we actually shoot anything. It’s just a lot of preparation.
In horseback riding, a rider will give commands by squeezing or lengthening the reins and altering the position of his legs. But when you’re on the ground — and not just off the ground but far away, out of camera shot — how do you let a horse know what you want it to do?
It’s a lot of gestures and body movement. You can stand behind the actor or off to the side and get the horse to move a certain way or do something by moving your arms. When horses are experienced, the gestures can be quite small. But usually it’s a lot of running from one direction to another.
How many horses did you use for War Horse? And how do you get them to all look alike?
We trained 14 horses of all ages and sizes but only ended up using about 10. War Horse follows the horse from a foal to adulthood, so we could fudge on sizes a bit. But color is important. We used Andalusians, warm bloods and only one thoroughbred — my personal horse, Finder. You try to get horses with a similar natural color but if not, you can always use makeup.
How did you shoot the no-man’s-land scene?
That was very difficult. But luckily, that scene required an adult horse so we could use one that was much more experienced. And we filmed it more toward the end of the film, so by then the horses had had a lot of preparation and were accustomed to the noises. For me, quite honestly, the most difficult scene to film was actually in the beginning, with the mare and the foal.
Why was that so hard?
Most movies that involve young horses always include a scene of the baby leaving the mother and coming up to the actor or actress, but in nature a foal never wants to leave its mother. It’s difficult to train a mother and her real baby, so we usually use another adult horse to play the mom. For War Horse, we had my horse Finder play the mother. He’s the true Hollywood star, always playing the opposite sex. Using him helped me eliminate half of the equation. Because I already knew how to control him, I could concentrate on getting the foal to do something.
How do you do that? I imagine it’s as difficult as directing a baby.
We have the real mother on set, behind the scenes. We’ll move her from one spot to another to get the foal’s attention. But we also have to keep the mother calm because if she gets distressed, then the baby will be distressed too. It’s a very delicate process.
You used your personal horse, Finder, a lot in the film. What’s he like?
He’s 12 years old. I worked with Finder on [the 2003 film] Seabiscuit and when it was over, I bought him. This year he’ll appear in the Snow White movie with Julia Roberts. He’s got one of the most unique personalities of any horse I’ve trained. Horses have specialties, just like [human actors]. Finder’s the one I use whenever I need a horse to appear wild or panicked or out of control. The horse can’t actually be out of control, of course, so it’s difficult for many horses to do that convincingly. In War Horse, Finder is the horse that breaks away from the officers when he’s first sold to the military, and we also used him to jump over the tank.
How do you get a horse to jump over a tank?
No, really. How?
I don’t want to give away my secrets, but it can be done. You do it in stages.
And use a lot of carrots.
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