To many he’s best known as Lucius Malfoy in the Harry Potter films. For some he was sociopathic mobster Michael Caffee – star of Showtime’s shortlived masterpiece Brotherhood, and he won a Bafta nomination for his portrayal of Harry H Corbett in BBC4’s The Curse of Steptoe. AND BBC1‘s Case Histories has proved a ratings smash. Yet Jason Isaacs was distinctly unstarry when HM met up with him to talk castration, black and white minstrels and smoking fags…

HM: How did you first get into acting?

“My first week at uni, I staggered into an audition drunk on subsidised alcohol after joining all these clubs. I had spent a week around this bunch of Sloane rangers, really out of my depth, pretending to be like them. There was a sign that said: “Can you do a northern accent?” And that was something I could do. It was for a play they were taking to the Edinburgh Festival. We thought it was very clever – about a Cabinet Minister and a rent boy – my character was castrated with a cheese wire!”

HM: Blimey.

“I know. And because I do magic, I had palmed a bloodbag into my underpants, so blood went everywhere. A couple of people in the audience threw up. One review called it: “the ultimate student, self-indulgent bilge.’ But another called it “electrifying”. That was my first dealings with the press. We put both reviews on the poster and sold out every show. 

“Back then, we all slept in the same room with one double bed and rotated every night. Finally, it was me and the lead actress in the bed – she was a Mrs Robinson to me, about 22 years old. She said, “are you going to do something, because if not I’m going to go to sleep!?” That might be why I became an actor.”

HM: Were you allowed back to the Edinburgh Fringe after the ball cutting incident?

“I was in a thing called The Black And White Minstrels, a CP Taylor play about race relations – with a lot of drugs and a lot of sex in it. It started with me walking on the stage in a nightie, rolling a joint, frying some bacon, hearing a car noise and going: “Fuck, fuck, if it’s that fucking cunt, tell him not to come in.” A lot of the Edinburgh ladies had thought it was the actual Black and White Minstrels – you could hear the seats slamming as they made their way out.”

HM: Would you like your daughters to follow you into the acting profession?

“If they did I would shackle them until the idea had passed! No, the actress thing would horrify me; it is a horrible world for actresses. I know some very successful ones, all the way through to unsuccessful ones, and not one of them is untouched by how much it chips away at their sense of self. The sense that their worth in the world directly correlates to how fuckable they are. It is better than it was, but it is still mostly true that scripts have a bunch of men, of various shapes and sizes and a woman that everyone is supposed to go priapic about.”

HM: You’ve had some amazing roles in recent years. How do you choose the parts you play?

“There are a couple of tests I apply when I am offered a job. Is my fridge empty? Is my wife sick of me being at home? Can I pay the bills? But mostly, I always wonder what I can do that will be fun and interesting for me, and that I can get away with and not be shit!”

HM: Is that what you thought about Case Histories?

“Well, I have avoided playing detective, I’ve managed to duck it through 20 odd years of being an actor. I just don’t like that genre. I don’t ever watch it. I don’t know what the point of it is. But Kate Atkinson’s books are much less detective-like and procedural. When I watched episode one I forgot that it was me in it.

HM: There were an impressive amount of smoking scenes.

“Yes, which has been very odd for me. I haven’t smoked for a very long time. There is the option to smoke herbal cigarettes, which health and safety would have you do on the set, but the crew are begging me not to because they are disgusting. It’s like being caught in a fire in a flower shop. If the character smokes in a scene and you shoot that scene all day, you smoke 50 a day. I made an absolutely solid oath before filming that I would not take a single drag off camera. That is absolutely what I did until the first day. Then I had a few drags off camera, which I convinced myself was just to keep it burning, and then I had a cigarette over Christmas. What I miss is obviously not the slow death or inability to get up stairs, but the feeling that it is naughty. You have to sneak outside or down an alleyway. There is something of the outlaw about it.”

HM: What’s your relationship like with fame?

“I have numbers of friends who can’t go out the door or walk down the street, and it’s awful – both for them and for you if you are hanging out with them. So I’m glad I made the decision to put Lucius Malfoy in that ludicrous blonde wig. 

“Part of my job is to hold a mirror up to nature, and be like the people I see. So you have to be able to see them, sit next to them on the bus or train. I occasionally get recognised, but very rarely. You could spend months with me walking round and never see anyone give me a second look. I like that. As someone who has been in the public eye, I have been asked to present things. I’d love to, but it is a dangerous path. I’m pretty aware that when I see people a lot as themselves, it makes it harder to believe in them as someone else. I don’t want to know too much about anybody.  It shouldn’t take you ten minutes to forget that you are watching someone who was just on Top Gear.”