Ettie, By Richard Davenport-Hines

Ettie, Lady Desborough, was born the rather plainer Ethel Fane in 1867, although her father was the son of the 11th Earl of Westmorland. Why is she important enough to merit a 450-page biography? It's hard to assess the importance of a society "hostess" figure – Lady Ottoline Morrell is her 20th-century equivalent – because so much of her fame rests on the people she knew, and who directed the times they lived in. Ettie herself didn't have that kind of power.

More than with any other biographical subject, our appreciation of the hostess figure is dependent on others' reports of her, rather than what she did herself, making us rely on friends attesting to her sparkle and warmth of personality, her goodness and her indispensability.

Ettie's alluring historical context helps, too: we can't get enough, it seems, of that late-Victorian transition into the "Edwardian afternoon", the glorious time just before the guns of the First World War destroyed a generation. Ettie played hostess at her home, Taplow Court, to "the Souls", a group of cultured and titled people that included a young Winston Churchill and HG Wells. She might have been married to a Whig MP, but she wasn't political herself, nor was she radical when it came to literature – James Joyce, like many other "modern writers", made her feel a "fatal and Victorian tendency to physical nausea".

Her life was sad: both her parents died young, as did her three sons, two killed on the battlefield. Her marriage was a happy one, but she took lovers, usually younger than herself. In spite of these human frailties and tragedies, Ettie is an example of an age utterly remote from the present day in its social codes and snobberies, and her role as the society hostess is gone forever. It seems hard to believe, reading this biography, that her world ever existed at all.