I expected these books to show that the rise and fall of Jewish business dynasties tracked the great sweep of modern Jewish history – from the faltering hopes of emancipation, first kindled in late 18th-century Europe, to the Holocaust. To my surprise, in most cases, their demise came earlier. Whether in Austria, Russia or China, it was precipitated above all by war and political revolution, not by the expropriation and extermination of Europe’s Jews. After 1917 many of the Poliakovs and Gunzburgs were already stateless. For those who fled Nazi Europe, or died in Auschwitz like many of Zinaida’s family, the Holocaust marked the end point in a long process of decline.