‘A picture has to be pleasant, delightful and pretty – yes pretty. There are enough unpleasant things in the world without us producing more.’ Such was the creed of Pierre-Auguste Renoir, the only Impressionist to emerge from an artisanal background, a rough-cut man who spoke ‘like a working-class labourer with a rasping, guttural Parisian accent’ but was devoted to making money out of sun-kissed, colourful and flattering pictures of the leisured bourgeoisie that have gone on to grace countless calendars, chocolate boxes and jigsaw puzzles.

One commission took him in 1881 to a hôtel particulier in fashionable Avenue Montaigne owned by Louis and Louise Cahen d’Anvers. Prominent among the Jewish banking dynasties of Belle Epoque Paris, they wanted a nice portrait of their two younger daughters, Alice and Elisabeth. What they got was certainly ‘pleasant, delightful and pretty’ – two plump and personable little girls, shimmering in silky white, pink and blue.

In her new book Catherine Ostler reconstructs the life stories of these two subjects and their family. She has done a lot of archival research, which she presents clearly and efficiently. But, as a former editor of Tatler, Ostler seems to have unlimited interest in the social whirl of the