ON SET WITH...

Kelly Reilly

Kelly, 40, best known for her role as series DI Anna Travis in ITV detective series Above Suspicion, plays fiesty drama Cantii warrior Kerra in Sky Atlantic drama Britannia. Here she take us behind the scenes on her new show, which was shot in the Czech Republic.

4 MONDAY

Britannia is the story of the Roman invasion of Britain in 43AD and the tribes there. My character Kerra is part of the Cantii tribe and is an amalgam of female warriors from that time. I haven’t been cast as an action hero before but it’s definitely part of the job description this time round, as the bruises on my body will testify! The key to the sword-fighting scenes – a few of which we’re filming today – is to rehearse them like a dance. I’m really pumped up by the time I’ve finished fighting!

5 TUESDAY

I thought filming in the Czech Republic would be a problem, as the series is set in Britain. But the show’s designers have worked hard to create amazing sets that allow you to feel like you’ve time-travelled – they’re so detailed and believable. Today we’re filming at one called the Amber Palace, built to look like Stonehenge, and it’s amazingly atmospheric. A ceremony led by Druids is being filmed and we have 300 extras dancing and playing drums, and a machine pumping out smoke under a full moon.

6 WEDNESDAY

Mackenzie Crook brings real power to the role of Druid Veran [right, with Kerra]. He’s so inventive to work with and he plays the role with madness and brilliance. That’s after he’s spent hours each day in make-up having his prosthetic mask fitted!

7 THURSDAY

Kerra has several enemies, not least the Druids who ordered her mother to be murdered in front of her when she was young. But her most bitter enemy is Queen Antedia, played by Zoe Wanamaker, the leader of the Regni tribe. While Zoe and I get on very well, the two characters relish the chance to trade insults. Zoe has got so bored calling Kerra a particular word that she’s asked the producers if she can call Kerra ‘copperknob’ instead, a reference to her flame-coloured hair, and is delighted to have been given the go-ahead for scenes today.

8 FRIDAY

The Czech weather is extreme: it was very hot back in the summer when we started filming, and now it’s freezing cold. The leathers and furs my character wears, which were making me overheat, are now a key part of keeping warm, along with five layers of thermal underwear! We were on a night shoot last night about an hour’s drive out of Prague and my whole body was shaking with the cold, to the point where, today, it’s aching. Hot water bottles are essential. The problem is, though, the hot water bottles get so cold so quickly. Roll on spring!

Britannia continues on Thursday at 9pm on Sky Atlantic