On Friday night, I went to Althorp, childhood home of Diana, Princess of Wales, to speak at its literary festival. My first duty was to appear on the panel of the BBC’s Any Questions? in a tent there. It was 30 years to the month that I had first been on the programme. Then it was at Uppingham School, presented by David Jacobs, and the panel included Roy Hattersley and Esther Rantzen. This time, it was presented by Jonathan Dimbleby, and the panel was George Galloway, Nigel Evans (the Tory MP who did not rape any men), and a beautiful woman called Rushanara Ali, the Labour MP for Bethnal Green and Bow. She was nine years old when I put in my first appearance. In all that time, the show has changed very little. It has retained its courteous, interested audiences and the camaraderie that comes from being in a town hall/stately home/local school rather than a London studio. From a panellist’s point of view, it is fun. The great difference lies in the subjects. Thirty years ago, it was Thatcherism (1984 was the year of Scargill’s miners’ strike). Now it is all about versions of the national question — Europe, immigration and the Islamist subversion of our culture.

Before the show, I was taken to my quarters, a huge, dark affair in the middle of the house called the Princess of Wales room. The bed canopy was so high it was cloud-capt. The wardrobes were so far off the ground that wooden poles were provided to hoist one’s clothes on coat-hangers to their distant hooks. In the room was a present, a book by our host, Lord Spencer, about the house. ‘Althorp,’ he concludes, ‘is, to me, the essence of Englishness. This is particularly so in its contradictions.’ I thought of this as our panel debated the Trojan Horse affair in Birmingham schools and the nature of ‘British values’, and George Galloway ranted beguilingly (if that is not too oxymoronic) about the wickedness of the West. My sense was that the almost wholly white, presumably largely rural or suburban audience did not quite want to contemplate the depth of the problem of educating Muslims in this country. Most of them, needless to say, were unsympathetic to Islamism. But many seemed also to resent Michael Gove for bringing the matter to their attention, and to enjoy the Galloway riff that all would be well were it not for Tony Blair. The undulating park at Althorp is really lovely. There is no colour except for the grey/brown of the trees, the white of the sheep, and the endless green as far as the eye can see. It is almost impossible to remember that Northampton is only 13 minutes away, with its 10,000 or so Muslims. What will become of them, and of hundreds of thousands of others all over the country? Will they accept their Britishness, or self-identify under a politicised banner of their faith? It may be the most important question about national unity since the Civil War.

I discovered, by the way, that the other important national unity question of the hour — the future of Scotland — is off-limits for this Any Questions?. It is treated by BBC rules as an election campaign, and so an exact political balance must be achieved. This involves having a representative of the SNP on every time the matter is discussed. This means, in effect, that it cannot be debated in England, which is exactly what Alex Salmond wants.

The following morning at Althorp the house was astir early for the authors’ breakfast. The number of guests and staff milling about made the whole place alive as in the Victorian age. In the afternoon, there was a cricket match between Lord Spencer’s XI and one fielded by Boris Johnson. The host team was strong, and included Maj-Gen. Mark Carleton-Smith, the Director of Special Forces. Boris’s team seemed to consist mostly of his family, including his sister Rachel. However, Charles Spencer excused himself briefly from our lunch table to meet Boris’s other team-member — name withheld from him — who was arriving by helicopter. It turned out to be Kevin Pietersen. It is this particular style of genially appalling behaviour which reinforces my belief that Boris could easily become Prime Minister.

Back home, I went to our hunt puppy show. The top dog was called Bedouin.

Looking at a photograph of the Buckingham Palace garden party on the Duke of Edinburgh’s 93rd birthday party last week, I noticed his handsome tie. Its overall effect was golden, but in fact it consisted of a series of tiny friezes of male historical figures. Who were they? I turned to Google in the hope of elucidation. I intended to type in ‘Prince Philip tie’, but my fingers slipped and I put ‘Prince Philip te’. Up came the following options: ‘temper’, ‘teeth’, ‘terminally ill’, ‘test results’, ‘testicles’, ‘templar’, ‘tears’ and ‘tea’. What a cruel medium Google is, and without even intending to be — just a faithful catalogue of the weirdness of the human race. I typed in ‘Prince Philip war hero’ to cheer myself up. I still can’t find out the meaning of the tie.

The good news of last week was that Alexander Chancellor was made editor of The Oldie, almost 40 years after he became editor of this paper. Alexander has replaced Richard Ingrams, who had resigned, expecting, perhaps, to be invited back. It reminded me of when Alexander was pushed out of his editorship of The Spectator 30 years ago. Richard resigned as its television critic in sympathy. I became editor, and made Alexander television critic in Richard’s stead, irritating his old friend. Now Richard is older, and even more irritated.

Another startling fact from the Great War, or rather, from just before it. The car in which Archduke Franz Ferdinand drove through Sarajevo 70 years ago next week bore the following number-plate: ‘A111118’ — the date of the Armistice more than four years later.