Richard Williams in The Guardian:
She took the title from a poem by Paul Éluard and her nom de plume from Proust. Years later, Brigid Brophy would declare that she wrote with “a pen saturated in French literature”. But 60 years ago , the publication of a first novel by an 18-year-old author had France's literary establishment in uproar. As a slender volume called Bonjour Tristesseflew off the shelves, Françoise Sagan became a scandalous success, the echoes of which would prove impossible to silence. Over the course of a long and eventful career, Sagan would go on to produce 20 novels, three volumes of short stories, nine plays, two biographies and several collections of non-fiction pieces on places, things and people she loved. But so powerful was the impact made by Bonjour Tristesse, and so profound the disturbance it provoked in French society, that it remains easily her best-known work.
This short novel of barely 30,000 words is a story told by Cécile, a 17-year-old girl holidaying on the Côte d'Azur with her widowed father, a roué who has brought along his young girlfriend. The daughter is exploring her own first sentimental adventure, a swiftly consummated romance with a handsome law student, when the unexpected arrival of an older woman, a friend of her late mother, disrupts the self-indulgent haze of high summer. First the newcomer takes charge, ordering Cécile to terminate her romance in order to stay indoors and do her homework. Then she and the father fall in love. To prevent their marriage the daughter devises an ill-fated plot in which the pretence of an affair between her boyfriend and the father's dumped girlfriend is intended to provoke jealousy and restore the status quo ante.
More here.