By now, one can safely assume that most people know who Viggo Mortensen is. A few years ago, it would have required explaining, considering that he was best known for having been in a few indie movies, playing Gwyneth Paltrow's lover in A Perfect Murder, a suitor of Nicole Kidman in The Portrait of a Lady, and John Gavin's role in Gus Van Sant's remake of Psycho.
Now, he is known for being Aragorn in The Lord of the Rings - the king who returns in the last one, literally the movie's poster child (a stylised picture of Mortensen scowling over his sword dominated the Return of the King campaign). By now, probably around a quarter of the world's population have seen him co-conquer the forces of evil in Middle-earth.
But life and careers go on, and Mortensen, 45, is now back on the road promoting his new movie, Hidalgo, directed by Joe Johnston (Jurassic Park III). Hidalgo is a good old-fashioned action movie set in 1890 about a real historical figure, Frank T Hopkins, played by Mortensen. Hopkins wrote about his adventures as, variously, a pony-express rider, a witness of the Battle of Wounded Knee, a player in Buffalo Bill's travelling show, and a participant in the Ocean of Fire horse race across the Arabian desert, riding his Native American mustang, Hidalgo, to victory against pure-bred Arab stallions.
It is this race that is at the heart of the movie. The hitch is that there has been a bit of debate about whether Hopkins took part in any of these events, apart from in his imagination, but more on that later. Hidalgo doesn't require Mortensen to speak dialogue on a par with Shakespeare, or even emote much, but he gets to do some of the things he does well, like show off his skill with languages by speaking a bit of Native American (he is reputedly fluent in Danish and Spanish), appear manly and chiselled, and ride horses beautifully.
In person, he looks as smooth and silky as a bond trader on a roll. He's wearing a dove-grey suit with a silvery satin tie that glints like a newly forged sword. I tell him, honestly, that I enjoyed the film, especially since I'm a bit of a sucker for movies with horses. "I like horses, too," says Mortensen, who apparently bought the horse who was Hidalgo in the close-ups. "It's one of the reasons I did the movie, but it's not the only reason. I wouldn't do a movie just because it had horses in it..."
I realise that Mortensen is a bit tense, like he's waiting for the other shoe to drop. I'd been expecting to find him in a jolly mood after Return of the King's Oscar success. But then, the other shoe, a great big iron horseshoe, drops with a thud when we move on to the depiction of the Arab characters in the movie, who are broadly brushstroked, but no more so than the film's other characters.
Mortensen is defensive from the off about the various ways that people have attacked the movie. It seems that historians can find no written record of the Ocean of Fire horse race outside of Frank T Hopkins own journals. Meanwhile, Arab horse breeders have taken umbrage at the suggestion that a mustang could outrun a pure-breed. So, for the next 15 minutes, in a manner not unlike Aragorn at the Battle of Helm's Deep, Mortensen takes on all these arguments at once with a filibuster of impressive ferocity as I smile, nod, and try to get a word in edgeways.
Here's just a taste of what he said: "People have started this, sight unseen, writing against this film. 'Oh, it's Bush propaganda, it's anti-Islamic!' they say. And there were articles written about it in Arab countries. And there are a couple of people who I believe are American, I think from Kentucky - it doesn't matter whether they're American or not - and they've not thought about why they're doing this, and claim to provide a wealth of research, and yet the places and people from whom I learnt the most about the story, they don't even mention.
"The most important source material is the oral tradition, particularly on Native American reservations. For generations, people have been telling stories, particularly about this guy Hopkins and his horse Hidalgo, and about this race. And the people who have been criticising the film also happen to be endurance riders and fans of the Arabian horse, like the people in the story, like Lady Anne..." he says, referring to a snobbish Englishwoman in the film, played by Louise Lombard, who wants her horse to beat Hidalgo, although she tries to seduce Hopkins, too.
He continues in this vein for some time. Eventually, I manage to say that maybe it's not even relevant whether Hopkins really did the things he did. "Yeah, but for the Lakota, for those who know the oral tradition, he is one of theirs and the horse is one of theirs," he says, passionately. "And for people to try to discredit Hopkins is, I think, an affront to them."
He suddenly apologises and laughs, seemingly having realised that he's been on his high horse about this one. Having been an outspoken critic of the Bush administration, it clearly stings Mortensen that anyone would accuse his film of being racist or jingoistic. After all, he wears a UN badge on his lapel to show his belief in what that organisation stands for.
By now, time has run out, and I say that's a shame because I wanted to talk to him about his work as an artist (of which one sees glimpses in A Perfect Murder, in which he plays an artist and uses his own paintings). Mortensen hands me a copy of his book Signlanguage, a creamy art book featuring his photographs and paintings. It's a touching gesture and I simper with gratitude as I leave.
Later, looking at the beautiful images in the book, I chance on a line written in capitals on a painting called Reading Richter: "but unfortunately you have to take the long way round every time". Words somehow fitting of this particular encounter with Viggo Mortensen.