You've never heard of David Duff ... I would put David in the same league as Theo Aronson. Hessian Tapestry is a wonderful book. I am sure he is still alive, but very elderly (b 1912) ... and living in Diss. I used to be David's researcher (for several books books published in the 70s and 80s.) I never accepted money, but I got other good things ... like long stays with he and his wife at their home in Diss -- and a beautiful signed photograph of Queen Mary (that hung over a toilet in his house -- his house was filled with royal memorabilia. This was not his comment about Mary, mind you.
The photo now is on a wall in my entrance hallway.
He also wrote bios on Princess Louise and Princess Beatrice (the Shy Princess) as well as bios on more modern royals such as the queen mother. His books are what I called secondary reading ... and I would say that Hessian Tapestry is his best book.
I happened to find this in Oxfam today for £1 so I bought it, obviously.
However, I've never heard of it before or the author, so I thought I'd check that it is reliable before I get stuck in.
It looks really interesting and there are some great photos I've never seen before. I couldn't believe my luck when I found it!