When you go through a difficult period in your life, or are feeling down, it’s common to turn to someone you know will make you feel better, who will comfort and motivate you. For actor Mark Farrelly that person was, perhaps rather unusually, the late Quentin Crisp.

“A long relationship had just ended,” says the 37-year-old from Sheffield, “and whenever I’ve felt low in my life, one of the people who’s always calmed me down and inspired me is Quentin Crisp because he was somebody who struggled and suffered a lot in life and went through long periods of isolation - he lived alone for most of his life and claimed never to have had a really deep love or relationship. His autobiography, The Naked Civil Servant, is just full of very calming wisdom.”

Looking for something “useful and productive” to do with all his new-found spare time, and to take his mind off his troubles, Mark decided to write and produce a play about his hero, and Quentin Crisp: Naked Hope was born. Mark took his one-man show to Edinburgh this summer and then to the West End, where it received great critical acclaim.

The show is in two parts: the first sees Quentin in his beloved but “grotty” Chelsea flat as the 1970s dawn; and then in his final years in his adopted New York, with the new millennium beckoning.

“I’ve structured it like that because I wanted to convey the idea that you can, like Quentin, feel that your life has passed you by, you didn’t quite get wherever you wanted to get, but then in his late 60s he was thinking ‘Well, that was it, I’ve come to the end of my personality, now I’m just waiting to die’, but this whole other avenue opened up in his life when he moved to America. It’s my way of encouraging people to hang on, if they’re going through a grim or disappointing stretch in life that seems to be lasting forever.”

Audiences seem to have been taking very strongly to heart this story of the man who, born Denis Charles Pratt in 1908 into a very conventional Surrey upbringing, flaunted his effeminate tendencies from early childhood and was openly and defiantly gay at a time when it was still illegal in this country, provoking homophobic abuse and physical attacks.

“I think he’s often remembered as being quite shallow,” says John, who has also written a play about the writer Patrick Hamilton and who is currently working on another about Frankie Howerd, “as someone who was quite effeminate and garish and promiscuous, but he wasn’t like that at all. He was an extremely thoughtful person.

“He never moaned, never complained, he was beaten up endlessly, he was shunned but, for such a slight man, he was as hard as nails. He was basically saying ‘I’ve got to be me and, in my case, that happens to be a very inconvenient and painful thing to be, but that’s no reason not to be it’. It’s ultimately about hope.”

l Quentin Crisp: Naked Hope is at The Old Town Hall, High Street, Old Town, Hemel Hempstead on Saturday, November 15 at 8pm. Details: 01442 228091, oldtownhall.co.uk