Tom Riley sounds exhausted. Living's phone interview with the star of new "historical fantasy" Da Vinci's Demons was scheduled for 8.30am UK-time but it's quite some time later before the operator is able to get through to him. It turns out this is a rare morning off for the actor and it's pretty evident from his initially sleep-slurred speech that he's rolled straight out of bed to take the call, though he's a good sport about it.
"It's not too bad," he says gamely, "I'm used to getting up at stupid o'clock, so nine is quite nice."
The reason Riley's feeling a little jaded is he's two months into the seven month shoot for Da Vinci's Demons' second season, which involves "five or six day weeks, and long, long, long hours". That would be a tough schedule at the best of times, especially when you're playing the eponymous lead character who's in almost every scene, but in this instance it's been exacerbated by an unusually brief break between making the first and second seasons.
"We were taken slightly by surprise by how soon season two came together," says Riley.
"The first episode of the series premiered in the States in April to gigantic numbers and within a week [US pay-TV company] Starz made a very bold sweeping decision of 'let's go again as quick as we can.'
"Which was exciting, but it did feel like the gap between shooting and going again was very short. And with all the publicity we had to do in the middle as well, we barely paused for breath. The good thing about that is it keeps up the momentum."
Also exciting "and a little terrifying", Riley says with a laugh, "was the sudden realisation we weren't just making something with our mates down in Wales that hardly anyone but our parents would see, but that it was going to be in practically every country we'd ever heard of and a few we hadn't."
Riley readily admits to feeling the weight of playing the lead role in such a big production, especially when it's such an iconic historical figure and the series has taken some serious liberties with his story.
"We aimed very much to be willfully anachronistic and entertaining, and not historically accurate. But even after we've said 'it's not what you think', because Leonardo da Vinci is such a recognisable figure, people always have expectations and go" - and here Riley adopts a posh, outraged accent - "'hold on, this is not what I thought!"'
At the same time as embracing the series' modern sensibility, Riley says he also "researched as much about da Vinci's early life as I possibly could - I went to exhibitions of his work, I read his letters and every biography about him, and then I tried to piece that with various modern diagnosis of his behaviour - whether today we'd put him on the autism spectrum and so on ... And yeah, the pressure was crazy, because I knew it'd all be on me if people didn't particularly like it."
Although it might not please the purists, Riley's interpretation of da Vinci as a sexy, swashbuckling genius is highly charismatic, while the series as a whole is a lavish combination of Borges intrigue and Da Vinci Code mumbo-jumbo mythology with a Sherlock-style super-smartypants at its centre.
For his part, Riley is most enjoying "the chance to really develop a character over hours and hours of screen time. That's what you look for as an actor and when the character is as complex and changeable as this one, it's just the biggest gift."
Da Vinci's Demons screens Thursdays, 8.35pm, on The Box, and repeats Mondays, 9.30pm and Thursdays, 7.30pm.