Nicholas Shakespeare's family memoir: How to survive Priscilla: The Hidden Life of an Englishwoman in Wartime France. By Nicholas Shakespeare. Harvill Secker; 448 pages; £18.99. To be published in America in January 2014 by Harper; $20.99. WHO exactly was Nicholas Shakespeare's Aunt Priscilla? He had grown up believing she was a war hero who had been captured and tortured by the Germans in France. The truth turns out to be far more intriguing. "Priscilla had learned," he writes in his wonderfully readable quest for answers, "that to survive one had to behave in an extraordinary way." Extraordinary, indeed. Priscilla, "a figure of unusual glamour and mystery" in the England of Mr Shakespeare's childhood, had moved with her cold-hearted mother to Paris at the age of nine. Her father - Mr Shakespeare's grandfather - Stuart Petre Brodie "SPB" Mais would have lost his job as a broadcaster for Lord Reith's BBC had they divorced. She grew to become mesmerisingly beautiful, even modelling for Schiaparelli in Paris. She was also unlucky in love. Her years in France included a horrible abortion and a sexless marriage to a French viscount. Devoutly Catholic, he waited until 1946 before at last agreeing to dissolve their passionless seven-year union. There was also a succession of affairs with men who ranged from respectable businessmen to black-market crooks. Her smitten conquests included Robert Donat, an English film star. More surprisingly for Mr Shakespeare, who had assumed his aunt had fought in the Resistance, they also, it seems, included a senior Nazi intelligence officer in Paris. As the Chichester Observer noted in 1950: "Until France was liberated she lived the life of a hunted animal." After the liberation she returned to England, only to become the wife of a tyrannical mushroom farmer. In short, the life of Priscilla Mais - or the Vicomtesse Priscilla Doynel de la Sausserie of Boisgrimot, or Mrs Priscilla Thompson of East Wittering - could read like cheap fiction. Happily Mr Shakespeare, a novelist and biographer of some note, is too good a writer to succumb to sensationalism. Instead, and after some impressive research, he builds a nuanced, sensitive portrait of this sad and glamorous member of his family, who died in 1982. Moreover, he places Priscilla in the social context of the 1930s and 1940s: from the devil-may-care years before the second world war through the tense years of the German occupation. Rigid social conventions at the time spawned a convenient hypocrisy, from the false titles adopted by couples "living in sin" in England to the flourishing brothels and sex-clubs of Paris. A similar story of convenience has long permeated France's view of itself under German occupation, one that pretends too great a role for the Resistance and minimises the extent of collaboration. As the life of Priscilla shows, surviving the occupation was too complicated an affair for any black-and-white verdict.