You once said you can only write about the past as it is the only language you understand. Could you please explain.

The present is too immediate, and I’ve gone beyond the age when I feel at home in it. My family lived in the past owing to my father having begun his working life as a whizz-kid in shipping and then been bankrupted in the slump of 1926. Ever after, he looked backwards, and made sure his children did the same.

Your last three novels have receded further into the past. ‘Every Man for Himself’ was set in 1912, ‘Master Georgie’ in the 1850s, and ‘According to Queeney’ in the 1760s. Is it more difficult to write about far off things and battles long ago?

The last three novels are set further back in time because I’ve written out my own past. Yes, it is more difficult, but only because events based on fact need to be accurate. Also you have to watch the language. But then you just read lots of letters written at the time and sort of copy the rhythm Also, I was lucky that my father used certain words and phrases that went back to Victorian times and beyond. If I hadn’t combed my hair he said I looked like the Wreck of the Hesperus.

Why are you so obsessed with Dr Johnson?

I’m not obsessed – I just found it curious that someone whose own writings are practically unknown and unread today should be so famous and beloved as a human being. Without Boswell, where would Johnson be? There’s also Johnson’s house in Gough Square. Just wandering round it brings him back.

What source material did you draw on for your latest novel?

Boswell, Mary Hyde, Joshua Reynolds, W Jackson Bate (CK), John Wain and the journals of Mrs Thrale, afterwards Mrs Piozzi. I also began to read Fanny Burney’s Evelina to learn about the landscape and what people wore, but gave up. She never describes anything, just says she’s gone to Vauxhall Gardens or Hampstead, and not a line about the houses or the clothes.

Are you permeated by what you read?

Yes, if they are things written at the time, by people who knew Johnson. I’m also affected by paintings and buildings.

How long did it take you to write ‘According to Queeney’?

About six months to actually write and complete, but there were long gaps in between when I just kept putting it off and making notes.

Have you been ‘called’ by by disembodied voices as the great lexicographer was himself.

Do you mean did I hear voices? Once or twice, particularly when standing at night in Gough Square, or when at Lichfield in the bedroom in which he was born.

Why did you write the story according to Mrs Thrale’s daughter Queeney?

Because I wanted the events described to be contradictory. Boswell’s version of what Johnson was like was magnificent, but who is to say he was not manipulated by his own way of seeing things? In my version, Mrs Thrale recounts the way it was, so does Johnson and so do the inmates of his household. Queeney contradicts them all, which is what I think always happens. No two people either view or recount a happening in precisely the same way. All history is inaccurate in the telling.

In your novel Johnson has a special. relationship with Queeney. What evidence is there for this) given that she merits just a footnote in Boswell’s ‘Life of Johnson’?

Boswell was not at Deadman’s Place or Streatham during the times I’m writing about. And it’s only with hindsight that he assumed such importance.

Can fiction be more truthful than biography?

I’m not sure. It depends who’s writing it. If you stick to the facts of someone’s life and manage to absorb the personality of the subject, then it’s perhaps possible to give a truthful, yet fictional account. After all, who knows what anybody is really like, or what they really think? The biographer – same as a painter of portraits – cannot help but reproduce himself to some degree.

Mrs Thrale gave Dr Johnson companionship and pleasures of the hearth. What did the melancholy old brute do for her?

He wasn’t an old brute. He was a mimic, a player of games, a speaker of great wit. No sooner had he made friends with Mrs Thrale than every great man of the time – Reynolds, Burke, Goldsmith, Garrick, Dr Burney – fought to be invited to her house.

Boswell had a famously low opinion of Mrs Thrale. In his biography of Johnson he says she has a slippery sense of the truth and she is a sycophant to boot. ‘Mrs Thrale, who frequently practises a coarse mode of flattery) by repeating his [Johnson’s] bon-mots in his hearing.) Was Boswell right or just consumed with envy?

Boswell was jealous. Not many of the men of that time had a good word to say of Mrs Thrale, partly because they resented her hold over the great man, partly because she was a woman. She possibly did get a few facts wrong. Johnson himself said she ought to be more careful in telling the truth, but he meant she wasn’t precise, not that she was a liar. And several people copied the way Johnson spoke, Boswell among them.

Boswell barely gets a look-in in your story and comes across as a bit of a toady himself. Aren’t you being unfair?

He doesn’t get much of a look-in because it would have been daft of me to have included him, seeing as he wrote the greatest biography of all time. My book would have become mutton dressed as lamb, if you know what I mean. The only reason he may come across as something of a toady is because those around him at the time couldn’t understand why he and Johnson were so close. Most of them thought him a buffoon.

Dr Johnson himself once likened Mrs Thrale to a ‘rattlesnake’ and she ended up slithering off with Queeney’s music teacher Mr Piozzi. Did she string Samuel along?

I don’t think so. He was fiftv-seven when he met her and she was twenty-two. Theirs was an equal friendship, in that she got the intellectual stimulation she craved and he got a home. It was Johnson, perhaps, who strung himself along, in thinking that perhaps she would settle into widowhood once Thrale died. I think he was too sensible to imagine they would ever marry, but then, like the rest of us, who can blame him for dreaming?

What would Dr Johnson’s wife Tetty have made of Mrs Thrale?

I don’t know. Ten years before Johnson met Mrs Thrale, Tetty was taking opium and drinking herself to sleep every night. I don’t think she went out much. I’d like to imagine the two women might have got on, but then the age gap was big, and Tetty was possibly fed up with people who talked about books.

His housekeeper Mrs Demoullins ­– did he or didn’t he?

Who knows whether Mrs Demoullins ‘went the whole way’ with Samuel. Certainly she told Boswell and Langton that she had been fumbled by him in the days when he was married to Tetty. She even said that she would have gone further if he had persisted, but every time he grew over-enthusiastic he thrust her away. But that’s what Boswell says she said.

Did Dr Johnson really eat sixteen peaches a day during his stay at Streatham Park?

Apparently. He was very fond of fruit, indeed of food, though he either fasted or gorged.

Dr Johnson said there are two things in life guaranteed to corrupt: praise and money. Have you been corrupted?

I have been over-praised, I agree, but then I always think it’s just people being nice, so it doesn’t really go in. As for money, I’ve really only had any during the last six years, so it hasn’t done any damage yet. And I do have a lot of grandchildren.