Richard had some experience on horseback prior to Robin Hood. We know the role of Epiphanes in the 1999 TV movie Cleopatra required him to do some riding.
But that was seven years before he attended Hood Academy and I believe he said he had to deal with some nerves in mastering Richie, Guy’s horse.
Even so, by the time he donned Guy’s black leather RA looked pretty darned good in the saddle. Of course, those powerful horseman’s thighs, the straight back and proud tilt to his handsome chin all played a role in how magnificent Sir Guy was astride a steed.
And as the show progressed and he spent more and more astride the horse, Richard seemed to gain greater confidence. He looked like a noble knight, even a king; if you didn’t know better, it would have been easy to think him the hero of the piece. All that horseback riding could only serve him well in preparing for his dream role of Thorin. Judging by the trailer, the King Under the Mountain will look positively regal, a true leader among his people.
the armitage effect 
James Nesbitt :
Who is the best and worst at the stunts, horseriding and so on?
“Richard Armitage is very good at the old horse riding because of course he did it in Robin Hood, so he’s very good at that. Of course he’s playing our leader, so it’s right that he’s good at that. Aidan Turner and Rob Kazinsky, they’re fit young men. But we’re all shapes and all sizes and we all have our own skills.”
http://www.digitalspy.co.uk/movies/at-the-movies/a307731/james-nesbitt-talks-the-hobbit.html
The more time he spends on horseback, the better Richard rides, the better he looks doing it. Be still, my heart … I really hope that the Richard III project goes forward with RA in the lead. The king was a soldier for much of his life, a general by the time he was 25, and he led from horseback.
I imagine him in armour, galloping along on a great steed . . . Yup, he’d make a great R III.
He does look as if he was born in the saddle, doesn’t he? A natural talent. 🙂 He looks so in control, so majestic..
He was made to play roles that require horseback riding. He’s got the horseman thighs!
He certainly seems to be a natural in the saddle. This scene from S2 ep10 always sends my stomach to the floor; the way he holds himself so straight and dignified in the saddle, but most of all, and you can’t see this in the pic of course, but if you know the scene…it’s his hips, *gulp* the undulation of his hips in rhythm with the horse…sends all kinds of naughty thoughts through my head! 😉
http://www.richardarmitagenet.com/images/gallery/RobinHood/album/seasontwo/Episode10/slides/rh210_093.html
Oh, yes, his undulating hips are very–eye-catching. And stirring. I could watch that scene over and over again.
He does ride beautifully. When he’s riding beside Robin in S3, you really see how wonderful he is. Robin is slouched and slumped in the saddle, but Richard is sitting straight, tall and magnificent!!
Yeah, I have used stills of the two of them together on horseback in videos and said, “Now, who is the hero (or star) of this show again?” 😉 It’s like Prince Richard, Peasant Jonas. Sorry, Jonas, you just don’t have “it.”
Now that is what I call one lucky horse 😉
One more thing I am jealous of–the horse. 😉