You have to be selfish to be an actor.

I am made Hand of the King which gives me an enormous amount of power, which I use quite ruthlessly - but skilfully - and Dame Diana Rigg joins us [playing political mastermind the Queen of Thorns] and we have a couple of really good sparring moments.

Power is always a corrupting influence. In this mythical time - let's call it medieval, feudal - people in power are dictatorial and don't want their positions of power to be threatened.

When you get to a certain age, the work begins to thin out.

It starts with the writing - which is really, really good. And the production values are phenomenal. HBO and Sky have spent money on it, and you get what you pay for. This has money put into it properly - not lavish amounts - but as each season is successful, they maintain the money that's being spent to maintain the quality.

On an independent film you're lucky if you get one, but ostensibly the job is the same. There's very little difference, apart from the knowledge that there's a captive audience at the end of it - which you can't always guarantee with a movie.

There is a huge fan base, they're very knowledgeable and very loyal. I was astonished - before I started working on the series I didn't know anything about Game of Thrones. I hadn't heard of the books. When it started going out, people were coming up to me in the street saying [fake cockney accent] "oh, Game of Thrones, f------ wonderful.