T here is an 80s pop song by Thomas Dolby, which begins “Tell me about your childhood”.But what if you couldn’t? What if the core question, who am I, could not be answered?

That is a question which has troubled oral historian Dr Rebecca Clifford for years. An academic at Swansea University who specialises in Holocaust memory, she has now produced an extraordinary book on children’s lives after the Holocaust, Survivors.

Clifford has combed archives to try to tell the stories of those born between 1935 and 1944, who would have been, at best, just ten years old when the war ended. Many of these children spent the war years, if not in concentration or labour camps, in hiding, perhaps fostered by non-Jewish families, but in any case in complete denial of who they were.

So many of the children who survived were too young to know their names, dates or places of birth. Add to that a frightening tendency on the part of these children, because of their experiences, to manipulate adults and tell them what they wanted to hear, and it became almost impossible for the stories of their childhoods to be told.

Adult survivors, for their part, too often dismissed child survivors, precisely because they were too young when they were parted from their parents; and even the restitution authorities took years to pay compensation, arguing that their qualification bar of “living in sub-human conditions” did not apply to children.

We read, early on, the story of Mina, staying in a post-war care home, Weir Courtney in Surrey, 11 years old and a survivor of Theresienstadt. Mina’s behaviour, writes Dr Clifford, “was puzzling: her language was stilted, and her emotions unnatural; staff recorded that they were worried by the false smile permanently frozen on her face. One day Mina suddenly revealed to care home staff how, during the war, she had seen her mother shot through the head right in front of her. Alice Goldberger, the matron of the home, believed speaking about the wartime past could be therapeutic for children, and she encouraged the girl to unburden herself of her painful memories. She recorded that, after this dramatic and sudden revelation, Mina’s behaviour improved… Staff at the home were thus dumbfounded when, six years later, the girl’s mother turned up alive, having never been shot through the head at all.”

Due to insistence by the various archives she consulted, Clifford was unable to use the full names of the children whose cases she highlights. She acknowledges that it is one more distressing way in which the children lose their identity, and says it is something about which she argued repeatedly. Her compromise, in the end, is to use the real first name and the real first initial of the child survivor’s surname. “It made me furious, and I had several people say they wanted their whole name in the book… these people have lost so much.”

Official post-war estimates by the American Jewish Joint Distribution Committee — the “Joint” — suggest that 150,000 of Europe’s Jewish children survived the war, of a pre-war population of 1.5 million. Though Clifford says this figure is generally used by historians, she warns that it raises other questions — “which children were visible to aid organisations… which children counted as Jewish? Which children counted as survivors? Who, indeed, counted as a child at all?”

Given the broken state of post-war Europe, it is astonishing that the aid agencies — including Britain’s Central British Fund, now incorporated into World Jewish Relief — were able to function at all. But they did, and Clifford is full of admiration for the work they did, dealing with children who were either orphaned completely, or had one surviving parent from whom they had often been parted during the war.

In Clifford’s own family, her grandmother Violet (born Ibolya) initially refused to discuss her wartime experiences. She had given birth to Clifford’s mother in Budapest and the family ended up in Canada. Only when Violet was 97 did she begin to talk to her granddaughter, urging her to tape the information. Violet died three years later.

Clifford began the research for her book six years ago. “It took a long time for me to figure out what I wanted and I was hugely helped by one of the librarians at the Holocaust Memorial Museum in Washington DC, Ron Coleman. He asked me, what would be your ideal document?”

This concentrated her mind and she eventually responded: “I wanted a document, or a series of documents, that will help me trace a single person’s life through time as they move through the decades. And he said, I have just the thing”.

What Mr Coleman produced was an unmatchable treasure trove, a box of documents all relating to the life of Felice Z, who became “my superstar. These papers were her whole life, right through from the desperate letters her parents wrote in an internment camp, right through to the present, and [showed] how she dealt with her past at various stages in her life”.

Using Felice as her template, Dr Clifford understood how she had to approach the research for the book. “I knew I had to look at the case files first. And then there were letters written to the aid agencies that had rescued her — so I knew I had to look at the aid agencies’ files”. Then there was correspondence with the restitution authorities, and personal memoirs.

Felice, who lives today in north America, did not find definite confirmation as to the fate of her parents — killed in Auschwitz — until 1982 when she was 42 years old. Her family — “parents David and Lydia, her older sister Beate, then aged three, and Felice, then one year old — had been deported from… Walldurn in … Germany to the internment camp of Gurs in the south of France”. Both children had been rescued from the camp by the Red Cross and hidden with French Catholic families until liberation. As a young adult until 1983, when the first American Gathering of Jewish Holocaust Survivors took place in Washington DC, Felice had been trying to fill in the gaps in her life story.

Her frustration boiled over at the Gathering, as older people told her: “You were a child, so what do you know?” But child or not, she was indeed a survivor, with just her and her sister alive after their entire extended family was murdered.

Once she was able to access the case reports, Dr Clifford could find the real names of the children and trace them through other archives.

There is, inevitably, heartbreak on almost every page of this book, as Dr Clifford patiently pieces together what happened to the children. One of the most poignant cases is that of Jackie Y, whose story is now comparatively well-known, but not at the time when Dr Clifford had begun her research. Jackie was one of the subjects of an academic research project carried out in 1945 by Anna Freud, daughter of Sigmund and a pioneer in child psychoanalysis. He and five others, all under four years old, had been in Theresienstadt, and came to Britain as part of a group of 300 children who survived that camp.

He was born in Vienna in December 1941, “but he did not know this”. Despite repeatedly asking his parents about his origins, after a boy at school told him he was adopted, he continued to be stonewalled. Dr Clifford says such denial was very common among adopted parents: either because of the stigma of infertility, or because immediately after the war, it was not yet legal to adopt a foreign-born child, and only fostering was permitted.

Eventually a dreadful scene took place when Jackie wanted to get married and had to provide proof to religious authorities in London that his biological mother was Jewish. In his unpublished memoir, he wrote: “My adopted mother assured [the official] that [my birth mother] was in fact Jewish, and that the document was in the safe deposit box, and couldn’t he take her word for it?” But that wasn’t good enough and Jackie’s mother was made to fetch the documentation. Jackie tried vainly to see the papers, but she refused. Instead he snatched them as she handed the material to the official. “To my utter astonishment, I saw that I had been in a concentration camp, and my real name was Jona Jakob Spiegel”.

His parents had fostered him from the Weir Courtney home in Surrey, and Jackie had no memory of his time in Theresienstadt or being the focus of Anna Freud’s study.

For Dr Clifford, this is a book not about Jewish identity, nor redemption as in a happy ending. Instead, for her, this is a book about memory — and how we know who we are.

Survivors, Children’s Lives After the Holocaust, by Rebecca Clifford, is published by Yale University Press, £20