How can a novel be lauded as a "masterpiece" when it is dressed up biography? Leslie

I understand your scepticism Leslie - many historical novels leave me cold. The characters seem to be modern day people in fancy dress. The test of a good novel is whether the characters come alive from the page.
The article mentioned Shakespeare's plays but a more recent example would be Tolstoy's "War and Peace": Natasha, Sonya, Pierre and Nicholas seem to be real people while you are immersed in the book. I would suggest just reading the first chapter of Autumn Laing and see if you become involved.