Julian, 66, lives with his wife Emma, 53. They have a son Peregrine, 25, who works in the film industry.
When I was young I always wanted to be 40, and when I got to be 40 it suited me so well that I don’t think I’ve ever really addressed the fact that I am not 40 now. I don’t have any nostalgia for my teens but 40 to 50 suited me to a T – you’re still young enough and all your body bits work.
My fascination with the British class system probably has its roots in the fact that I was the child of an unequal marriage. My father came from one of those families while my mother’s father was a civil servant. In 1935 that was a huge difference. They were very happy together but his family was unkind to her. When I was about 14 I began to understand what was going on and eventually it became something I could express.
I spent some of my childhood in Africa. My father, initially a diplomat, joined Shell in about 1953, eventually becoming head of Shell in Nigeria.
At school, I enjoyed acting and did more while I was at university. I loved films, then realised that a job and an interest didn’t have to be separate things. I wanted to spend my life in films and the obvious way of doing that was to become an actor.
I got myself into drama school – and then I told my parents. My mother was amused. My father didn’t have a principled objection but didn’t think I’d make a living. But they did pay for me to go there.
One of the film scripts I wrote was shown to director Robert Altman, who was trying to find a writer for the film that became Gosford Park. In 2000, he interviewed me over the telephone. I sent some character ideas and then I was commissioned to do the first draft. The film was released in 2001.
Gosford Park was the inspiration for Downton Abbey. Maybe it was a bigger hit than most period dramas because we didn’t make a distinction between life up and down stairs. The characters were basically decent men and women, just trying to get through life.
My new book, Belgravia opens in 1815 on the eve of the Battle of Waterloo at the Duchess of Richmond’s now legendary ball. Something happens there that will affect two families. Jump forward to 1841, to one of the great houses in Belgrave Square, where the two families meet again. One is very established, at the peak of society, while the other is a supplier to the Duke of Wellington turned property developer and relentless social climber. If the secret from the ball is let out of the bag, one of these couples will be destroyed.
Belgravia (Weidenfeld & Nicolson) is out now on loot.co.za