On the private lawns outside the white Nash terraces that grace the east side of Regent’s Park where he lives, A. N. (Andrew) Wilson is lamenting that he hasn’t had much work to do. For our most prolific living author and journalist, whose many novels, biographies and histories grace every erudite house-hold in the land, it’s a puzzling remark, until he qualifies it. ‘I’m the lawn monitor. Because it’s rained so much this summer, I haven’t had to do much mowing.’ Ever since Rugby and Oxford, when Mr Wilson burst upon the world with his life of Milton, he’s never been far from London and the literary firmament.

His Monday books column in The Daily Telegraph is required reading, and his three most recent works, The Victorians, After the Victorians, and the novel Winnie and Wolf, about Wagner’s daughter-in-law’s imagined affair with Hitler, are the latest in more than 30 published works. Just out is Our Times, in which Mr Wilson has captured, with his prodigious intellect and eye for often-gossipy detail, Britain over the past 50 years.

‘The one constant has been the Monarchy,’ he says, as we sit before an open fire in his Regency library. He writes here each morning, in longhand or with a portable computer. Now 57, and married, with a young daughter, to the architectural historian Dr Ruth Guilding, Wilson always knew he would be a writer. ‘I was a solitary child and my elderly parents understood my sense of solitude.’ His father, having fought in the Second World War, was managing director of Wedgwood, and their time as a family, with two elder siblings, was split between Staffordshire and a house in South Wales, where Andrew spent much of his childhood.

‘When I think of Britain today, with its multiculturalism and rise in Islamic extremism, it seems so far from the good and decent England of my parents.’ He laments the decline in churchgoing and the rise of post-Darwinian deconstructionist thought popularised by such writers as Richard Dawkins and A. C. Grayling. Yet he concedes that in our lifetime, with only 2% attendance, the Church of England will be disestablished. ‘Attention will have to be paid to the rise in Catholicism here.’

Mr Wilson, like his hero John Betjeman (another subject of an A. N. Wilson biography), is as at ease in clubland as on a coastal walk (he has a seaside home in Cornwall), and he’s not afraid to shoot an arrow into the political arena: Roy Jenkins he calls a plagiarist, Germaine Greer a ‘latter-day buffoon’, and the late Duke of Devonshire, a friend, a true ‘Social Democrat’. Of Lady Thatcher he says: ‘She was the best Prime Minister of our lifetime,’ and he describes Oxford University’s refusal to grant her an honorary degree as ‘shameful.

In fact, since that moment, Oxford has been going down the drain ever since.’ Nor is he a stranger to popular culture, having covered as a journalist the Fred West murder trials and the phenomenon and tragedy that was The Princess of Wales. Talking about the rise of Punk, which is covered in his latest book, he says: ‘I may not know the music of the Sex Pistols, but I know what they meant.’ They come under his approval for ‘Conservative anarchy’. Strange, perhaps, for such a serious writer is Mr Wilson’s admiration for good and honest journalism.

‘It’s deep honesty that distinguishes a gentleman,’ he says, quoting John Osborne about Betjeman. He could also have been referring to himself. A friend at any table, Mr Wilson pays tribute to the importance of Private Eye. One recalls with warmth his own journalistic scoop for the Spectator in the 1990s when dining with The Queen Mother, she told him she was having trouble getting an overdraft and enjoyed The Waste Land. Mr Wilson is an optimist. He sees what has improved over the past 50 years: ‘Better dentists, doctors, cancer treatment, provincial hotels and drink, much better drink.’

He is also full of admiration for Radio 4. No one ever left Mr Wilson’s company, and I have shared it often for more than 20 years, a less wise or less thoughtful person. What could be less selfish than to share your solitude? And although there may be devilment in his detail, there is God in his vision. ‘Our Times’ is published tomorrow (Hutchinson, £25). Mr Wilson will be speaking about it at Cheltenham Town Hall at the Cheltenham Literature Festival at 10am on Wednesday, October 15 (0844 576 8970; www. cheltenhamfestivals.com)