Christopher And His Kind explores novelist Christopher Isherwood’s formative years in the run-up to the Second World War and airs at 9.30pm tomorrow night on BBC Two.

Director Geoffrey Sax (Doctor Who: ‘The Movie‘, Stormbreaker) told CultBox: “The shoot was 22 days – for period drama that’s incredibly tight. We had to shoot fast, especially with the scale of the piece. It was very, very tight: there’s music in it, there’s action and you’re trying to dramatise the rise of the Nazi party!”

Speaking about the shooting location, he revealed: “You know, when I first went to Belfast I was kinda surprised, because I thought it’d be very hard to find anything there. I had been there before and I hadn’t immediately thought “this looks like Berlin”.”

He continued: “To be truthful, when I first went there with Celia Duval, the producer, we had a walk around and we were at a slight loss about how we were going to do it. But when we went with our production designer and location manager, we started really nailing down what we could do. With period drama, it’s all about parts – you pick your angles. It’s as much about what you don’t see as what you do see.”