Let’s move on to your five books. Your first choice is Sarah Bradford’s book about George VI – who’s been talked about a lot recently, on account of the Oscar-winning film, The King’s Speech.

I like Sarah’s work; she is very diligent and a thorough and a very skillful writer.  I think this is perhaps her best book because she got a degree of distance from the subject – obviously through time. And she was given a lot of access to documents. I thought she painted a vivid portrait of the man. The response to his death was very touching. We forget that people lined the railway track as his coffin was taken from Sandringham back to London. 

What about his relationship with Churchill, which was described in the book as a great wartime partnership?

For me, the book goes further than that. It’s the relationship between George VI, the Queen Mother and the Roosevelt family. I would always argue that their visit to America in 1939 was probably the most important Royal visit in the last century. In the face of American isolationism, it helped push the American elite away from their tender warmth toward Nazi Germany and feel closer to the British. So that, for me, was a turning moment. The whole abdication crisis is also described, as well as the relationship with Churchill that you mention.

A good book to read, especially as it all is so much in the ether. Your next choice is Ben Pimlott’s biography of the Queen, in which he sets out to show her more personal side.

Yes. Ben was the head of Goldsmith College and I got to know him a little bit before his sad and premature death. For a Labour Party man, he had a very keen and sceptical eye of the royal scene. He was also given very good access, for once, by the Palace.

Why do you think they let him in, considering his credentials?

Because his credentials were both left-of-centre and academic. He was a worthy adversary very much up to the job. I think he painted a very skillful portrait of the Queen ,who has always been quite an enigmatic, elusive character. He painted in rather more subtle shades than the caricatures – for example, he looked at her relationship with Prince Philip, and I think he was particularly good at looking at her relationships with politicians and the wry way in which she observed these things.

She is meant to have a good sense of humour and to be a great mimic as well.

Yes exactly – but obviously we never see those qualities. She is someone who is always slightly stony faced. 

What do you make of her and in particular her relationship with Princess Diana?

She found Diana just puzzling; she couldn’t really make her out. Diana was always very respectful of the Queen. When I was asking her questions about the Queen, she would never dream of criticising her. But there was this feeling that the Queen should have been tougher on her son and his relationship with Camilla. Diana always felt that she inevitably sided with her son in the face of overwhelming evidence that he wasn’t behaving properly.

What about her relationship with her grandchildren? In particular William, whom you’ve been writing about.

She is very indulgent of her grandchildren in a way she wasn’t with her own children, which is a typical way for grandparents to behave!  I know – I am a grandfather. When William was at Eton, he would go off to what he called WC, which was Windsor Castle, to have tea with his granny every weekend.