There is now a well-established genre of refugee literature, where people who fled Nazi Germany, Austria or Czechoslovakia tell their stories before their generation dies out. Such stories are often fascinating, but their authors’ primary purpose – telling the story before it is forgotten – is to convey to the next generation what it meant to be a refugee, what was taken away and what was gained in terms of freedom, life and opportunity, along with a sense of not belonging anywhere.

But this book is different. At its heart are three Jewish sisters, born in Berlin: Marianne (Simon May’s mother), Ursel and Ilse. This is the story of how they convinced themselves and indeed others, including senior members of the Nazi establishment, that they were not Jews.

May explores a denial of their Jewish roots so strong that it was utterly internalised. They believed it. He traces its intellectual and social origins to the Jewish women salonistes of the 18th and 19th centuries, such as Rahel Varnhagen, and to the poet Heinrich Heine. These two were committed