If you think his reputation overly elevated, try to imagine any world leader of recent times winning the Nobel Prize In Literature, as he did in 1953. His is some story, but one that presents a massive challenge to anyone trying to tell it. How do you write words for Winston Churchill, put fitting phrases into such a memorable mouth, create witticisms worthy of him, actions characteristic of him? To write the screenplay – the real story of how close he and Britain came, in May 1940, to doing a peace deal with Adolph Hitler, and so surrendering central and Western Europe to Nazi rule (unthinkable now) – there'd also be mountains of research to wade through in order to correctly portray both man and times. I'd have to show him as an immense wit in times of crisis, wooing his wife, a bully with his colleagues, a man at once certain of himself and at the same time full of private doubts. So intimidating was this writing challenge I simply shelved the idea, for more than a decade, back there where many other good and bad ideas, then and now, are gestating/incubating/suppurating/vegetating/festering…(You see what is happening here?

This is how Churchill affects you: just as in the marked-up original manuscripts for his greatest speeches - deletions and insertions of words everywhere - Winston's infernal/eternal search for the right word, the crucial word, starts to become your own, not letting up until you get something close to the right ones in the right order.)

But then, four years ago, after the happy experience of making The Theory of Everything, I felt a little braver and so blew the dust off this old idea and tried to take the Churchillian position that it was better to go down fighting than never to have fought at all.

With this the research phase began.