He had three months to transform himself into the brooding romantic hero, which is “a luxury for any actor. It gave me tons of time to keep reading the books and the script,” the 32 year-old explains, “and to figure out how I see the character and mentally prepare for it, get the accent down, get in shape, have horse riding lessons…”

And yet come day one on set, all that preparation went somewhat out the window. “I remember the first day so well. I was horse riding in the very first scene and thinking, ‘Jesus, if I blow this, it could all be over - I could be off!

“It’s quite flattering really, thinking, ‘They believe in me and trust I can do it!’ But there’s a little bit in the back of your head worrying, ‘I hope I don’t let people down…’ But in this game you have to get over that very quickly. Self-doubt can sometimes be a good thing, but you need to keep it in check – it’s all a confidence game, really. You can’t let it beat you.”

How to…be Ross

“It always comes back to the script. Keep reading the script, keep reading the books, and that will inform you and what you have to do. It’s a really organic process. I didn’t see the last TV adaptation because Winston Graham’s novels and Debbie’s scripts were enough for me and I wanted to find Ross Poldark myself; I didn’t want to be swayed. I’ve hung out with Robin a few times and he’s a lovely fella, I think he forgives me for it!”

...Get the look

“When the offer came in and I read the book, there was a moment when I went, ‘Let’s not go to the barbers, let’s keep this long, see what they want to do with it.’

“My Poldark is based on his description in the books and how the producers saw the character. With the scar for example, Jacqui Fowler, the make-up artist the first year, just put the scar on the left side of my face – we never gave it much thought, and it’s never mentioned in the book which side the scar is on - and then we discovered Robin Ellis had it on the other side!

“Physically I saw Ross in a certain way. He’s strong, does a lot of manual labour, if he’s not on the horse he’s down a mine, he’s building stuff, he’s got a farm, it just made sense for him to be fit and strong. So I went to the gym a bit more, ate a little less, all those boring things. Unfortunately there’s no little pill you can take to grow a six-pack.”

...Grasp the accent

“Poldark is a Cornish character, but the family was quite wealthy and well-respected, and Ross would have gone to public school, so he probably wouldn’t have had a Cornish accent. It just made more sense not to have it. And I’m sure it made my life easier! We had a really good voice coach on set but my English accent is pretty practiced – for a lot of Irish actors it’s a second tongue, having grown up watching the BBC.

“I’ve never really given the Cornish accent a proper go though, and there is something about it that is a little bit like Irish, so maybe it wouldn’t have been a million miles away from my own voice. I might have looked a bit more foolish though if it hadn’t worked. When I listen to Jud and Prudie I can’t understand a single word of it! And even Demelza at times, I look at her script, which is written phonetically, and I can’t work any of it out.”

...Ride a horse

“I’d done quite a bit of riding in New Zealand for the Hobbit but I was by no means an expert! I’m an actor, dahling, I’m faking it! You have to look like you’ve been doing it all your life. I went to a brilliant horse trainer in Yorkshire for a couple of weeks and got more comfortable in the seat, basically.

“My horse’s name is Seamus. He’s a cool, Irish horse, so we get on great. He’s a celebrity now and has a lot of people visiting him at his stables – apparently they all rub his saddle for some reason, I have no idea why!

“I’ve just come back from LA and I was horse riding over there quite a bit - a few pals have got horses and we were out riding around, but producers seriously don’t want to hear that. It’s fine when it’s a few months before I start work again, but if I come off a horse in the middle of a job and hurt myself, it tends to aggravate the people paying my wages.”

...Go underground

“I went to Cornwall a couple of times before filming started - I’d never been prior to taking the role on - to actually go down some mines and see what the whole deal was. There are still a few working mines. It’s a very honourable and noble profession, a very ancient one, and it’s respected, but it wouldn’t be my cup of tea. It’s incredibly claustrophobic and dark, and y’know, you’re talking to an actor, we’re all lazy and the thought of manual work… I’m 32, I’m not scared of the dark anymore but the idea of spending all that time underground when it’s so beautiful above! When I got back to terra firma again, I took a deep breath and thought, “Thank God I’m back up in the sunlight.”

...Scythe a field

“Anyone who knows scything looked at that scene and thought, “Oh, dear God, what is he doing?” A couple of experts criticised my technique and they were dead right to!

“There was actually an expert there, looking at me while I was doing it and shaking his head. I’d go back and say, ‘show me again,’ just to make him happy, and then I’d get back in front of the camera and carry on swinging it around again…

“He did say to me: ‘That’s ridiculous – you couldn’t do that for 10 minutes, you’d be exhausted. You’ve got a whole field to do here!’ But I only needed to do it for 45 seconds and I was obviously never trying to be a pro – it just had to look effective, and I think I did that. The real technique isn’t quite as dramatic. I do respect where he was coming from though, and we do have experts knocking around to keep us in check, especially with a period piece that has to be true to the time.”

...Swim for the cameras

“I’m a strong swimmer but to be honest with you, I don’t know if there was much swimming involved in the scenes of me in the water. It was more thrashing around Timotei-style for a couple of minutes – not much swimming going on there!

“The sea was gorgeous though. It was the height of the summer, it was really warm and we had this private beach - it was glorious.”