To start with, Colegate takes the fashionable, Edwardian stereotypes and looks behind their masks, the sporting lords, the fashionable wives, yawning with boredom in the country and aching for a cinq-a-sept with their London lovers. She gives us the Jewish banker and the European nobleman, the girl making her debut, the former court favourite deprived of her fun by the death of the King. This recent Royal demise is used to shadow the world of pleasure with a coming, darker era and we are reminded of the replacement of King Edward’s highly entertaining, social fireworks with the dreary court of George V. We have the intellectual opposition represented by the blue-stocking daughter-in-law and the anti-blood-sports demonstrator. We are exposed to the dreams of a visionary gentleman, as well as to the despair of a clever woman trapped in marriage to a fool. They are all brought before us for our examination. We knew many of these types, as types, before we opened the book but now we learn what it is like to be inside their heads.

What makes this work peculiarly satisfying is its absolute authenticity. Isabel Colegate belongs to that small group of ‘silver fork’ novelists who actually know the real workings of the world they write about, the world of the highly privileged. It is a small club. Jane Austen belonged to it, along with Edith Wharton, Marcel Proust and Anthony Trollope, Thackeray at a pinch. But not Dickens, whose aristocratic characters are the black and white projections of an enraged outsider, and not Coward or many others who only entered those gilded portals when success had reclassified them socially. Colegate has the secure observation of the insider who knows these people well and was watching them long before they began to be afraid they might figure in one of her novels. She neither hates nor worships them but is simply striving to understand how they could have ruled since the dawn of recorded time and then, in the space of less than half a century, have entirely lost their grip on the political and public life of the Nation. These faults, she seems to say, are the reasons why the old world ended and these other elements are the benefits that we lost when it did. It is this inter-plaiting of the positive and the negative aspects of benevolent paternalism that make the novel so complex and so rewarding.

Lord and Lady Hartlip – Gilbert and Aline – are the embodiment of one popular view of the period. He, the crack-shot nobleman, taciturn and finally devoid of honour, for whom sport has replaced all meaningful activity in his own scale of importance. She, by contrast, is definitively frivolous, the licentious, socially ambitious parvenue in haute couture. It was suggested when the book first appeared that they might have been modelled on the Marquess of Ripon and his wife, although she was not, as it happens, a social climber (she was born Lady Gladys Herbert) but she was certainly one of the grandes horizontales of the era.