Lee Jones wasn’t much of a horseman before filming began on “The Bastard Executioner,” but now riding horses is his “new favorite thing.”

That’s just one of the changes in the Australian actor’s life since he landed the title role in the medieval drama, which debuts at 8 p.m. Sept. 15 on FX.

Jones plays Wilkin Brattle, a 14th Century knight who gives up his sword to lead a peaceful life as a farmer and husband in a small village in Wales. But when the Welsh uprising against English oppressors leads to personal tragedy, Wilkin reclaims the blade to seek revenge. Yet he struggles with the path he takes.

Although viewers will get plenty of sword fighting, castle intrigue, beheadings and horseback riding, Jones said the relationships between characters and Wilkin’s internal conflict are most fascinating to him.

“He’s perhaps losing the ability to trust himself and he’s a very spiritual man and I think … his faith is wavering at times,” Jones said during a recent call with reporters. “He’s really trying to find who he is at his core, I think. That’s really what his journey is.”

Lee Jones

Wilkin Brattle (Lee jones” battles the Scots in “The Bastard Executioner.” (Ollie Upton/FX)

With just a few TV and movie credits to his name, Jones, 32, was known primarily as a theater actor in Australia. But after an acclaimed turn as the creature in a 2013 production of “Frankenstein” for Sydney’s Ensemble Theatre, he began shuttling between Sydney and Los Angeles to launch his film career. He auditioned for “TBX” creator Kurt Sutter in February and was on location in Wales two weeks later.

“Things have gone from zero to 100 very quickly,” Jones said. “And I feel like everyone in the cast and the crew have been really supportive.”

That support is key for the actor, who has had to adjust to his new life in many ways. He’s not only away from home to film the show in Cardiff, Wales, but in his first turn as a TV series regular, he’s playing the lead role. The scale of the show—set designers built a village and a castle specifically for it—is epic.

He seems to be embracing the challenge.

“It’s been one of the best things about this job—getting to sort of develop a different skill set,” he told me during the call. “I’ve been craving doing more film and TV and it’s been a great lesson on working off instinct and working really fast. And I feel it’s allowing me to flex a different muscle and that’s been really enjoyable.”

Jones already is earning praise from Sutter, director Paris Barclay and his cast mates, which include Stephen Moyer and Katey Sagal. He’s preparing for fan reaction, but the work itself is his priority.

“Just to have the chance to do this and just to work on something so creative and satisfying and epic is just sort of [amazing],” he said. “I know things are going to get perhaps crazy; [that] is what people are telling me.”

Yes, they are. The last time Sutter dropped a relatively unknown actor into a lead role— for his “Sons of Anarchy”—Charlie Hunnam became a TV star and object of affection (obsession?) for many fans.

So is Jones ready to be a star? “I guess we’ll find out,” he said, laughing. “I think if I started thinking like that—I don’t know.”

More about Lee Jones

He loves acting. (Watch the clips from his role in “Frankenstein” below.)

“I’m very hardworking and dedicated to the craft really. That’s why I’m enjoying this so much, because I’m getting to really do some of the best creative work of my career so far.”

Here is a clip of Jones in “Frankenstein.” Watch Jones and his cast mates rehearse in this Sydney Morning Herald video.

He really wanted to be “The Bastard Executioner.”

“Look, as an actor selfishly you go, ‘Wow, this guy, he really goes through everything.’ I get to explore the full range of human emotion and it’s just a great role. I hadn’t read the script but I’d heard about it and I just thought that’s for me. I don’t know why but dark things fascinate me. I like exploring heavy material as an actor, I really do. So that pulled me to it.”

That body didn’t just happen.

“I was an athlete; I was a swimmer before becoming an actor.”

Lee Jones

Lee Jones as “The Bastard Executioner” (left) and in 2013.

He’s had to adjust his sword fighting technique.

“I’ve done a lot of sword fighting on stage before and so getting rid of the stage aspects and being really extra wide and safe on stuff—that was what I focused on. The stunt guys have got me doing some boxing footwork and that keeps me light on my feet and keeps the swordsmanship looking quite fluid actually.”

He’s obsessed with horseback riding.

“I love it. It’s my new favorite thing. It’s really exhilarating and helps me. Any day I’m on the horse I’m happy and the scenes kind of take care of themselves.”

Lee Jones

Lee Jones got into riding horses while playing Wilkin Brattle in “The Bastard Executioner.” (Ollie Upton/FX)

The role is teaching him things about himself.

“I’m enjoying a lot of myself in this and that’s what you have to do, especially in the case of TV. I think I’m having a great time actually seeing my strengths and my vulnerability. That’s kind of the key to the character and I’m enjoying that. It’s been interesting.”

He seems to take things in stride.

“The speed at which TV goes has definitely been something I’ve had to adjust to. But that’s been great in itself because in theater you just sit around and think too much. And now we just have to trust our instincts like I said. Working at a great pace can really help the work I think. You can’t get in your own way.”