‘Go and get back what was taken from us,” my eldest daughter said as I left the house to meet my brother at the German embassy in London. We had to attend in person to receive our naturalisation certificates, and I had little notion of just how powerful a moment this would prove to be.

My mother, Eva, was seven when her family left Berlin in 1939. They were assimilated Jews, born in Germany, with a business, friends and family. My grandfather, Emil, was arrested on Kristallnacht and taken to Dachau concentration camp. He was released weeks later with scarlet fever after my grandmother, Irma, had paid a large bribe. While she waited for him to come home, she had booked passage on a boat to Thailand, the only country that would accept Jews without visas in 1939. But my grandfather was so ill, they missed the boat. My mother’s family were then among many Jewish families sponsored into Britain by the Rothschilds. They waved goodbye to both sets of grandparents, who refused to leave and subsequently died in concentration camps.

This is just a short summary of what my family lived through. There are no adjectives to describe the grief, the horror, the fear and the loss of home, family and everything they possessed.

Reclaiming German citizenship felt hugely symbolic as I went to meet my brother, and not just because of the timing – it was 8 June 2017, general election day. I had been diagnosed eight months earlier with triple negative breast cancer, the most aggressive and least easy breast cancer to treat. And it had metastasised. I knew I might not live long enough to use the passport, but the urge to draw a line under the miseries of the past was strong. The one thing that really matters with a shortened life expectancy is to bury every hatchet of regret and unhappiness, so that I can live free from that past in the time I have left.

Genocide doesn’t just traumatise those who live through it – such epic persecution tumbles down through the generations, distorting “normal” family life and corrupting love. As a child I knew only the vaguest outline. I never knew the details of what my mother’s family had lived through, because it was never talked about and I knew not to ask. They never bought German food or wine, and Germany was the last place on Earth they would have wanted to return to. I recently discovered that, during the second world war, my grandfather worked with the Allies as an interpreter for German prisoners of war. He was advised to change his name from Unger to something less “Jewish” in case he should be captured, but he refused and went all the way back to Berlin as the war ended. How I wish I could have had just one conversation with him about his experiences before he died when I was 15. I cannot imagine how it must have felt to return to the rubble of the city of his birth after everything he had been through. But silence was the only response for Jewish refugees who had survived the war. There weren’t the words adequately to express their anguish, and it was far too painful to revisit. They needed to cut off that past just to be able to move on and make the most of their luck. And it was this admirable resilience that helped my grandparents build up a new business selling zips and buttons, and their dream retirement bungalow home in the middle of a Sussex field.

Kate Figes with her grandmother, Irma, and brother in 1961. Photograph: Courtesy of Kate Figes

As a child, I couldn’t help but breathe in all of that suppressed emotion without the intellectual sophistication to make sense of it. There always seemed to be inexplicable anxieties, which went into orbit whenever it came to travelling – for obvious reasons. Money had to be saved and spent carefully, that suitcase always packed in the hall in case the creep creep of antisemitism should happen again, and I still squirrel away every penny for that rainy day. And all of the rage, grief, loss, humiliation and guilt at having survived when others had not had to come out somewhere, and it usually did within the family, because it couldn’t be expressed in any other way.

My mother always said my grandmother took out on her all her rage at everything she had lost, and I saw as a child how hard it was for them to show affection towards each other.

For the last decade of Nana’s life, she refused to see my mother. “It’s better that way, it’s all too painful,” she told me. She kept to her word: they saw each other only once more to my knowledge, on my wedding day, and my grandmother even refused to see my mother as she lay dying.

Restoring our citizenship is the least the German state could do, but that small gesture feels healing and uniting

I have always attributed all this family heartache to the legacy of the Holocaust. They could not talk about it. They could not bury and therefore mourn their dead. I think, too, that the effort involved in getting her family to safety, then living through five years of war, in fear of a German invasion, meant Nana’s nervous system must have been on permanent high alert. And yet when I once dared ask her how she had managed to cope, she merely said: “It’s best to forgive, but not to forget.”

That history is something I, and other second- and third-generation Jewish descendants, cannot forget, either. It has been handed down through the gene pool and throws an ominous shadow over the past, just as cancer does over my future.

It’s an honour to carry that torch, but it can also feel like a ball and chain, dragging me back to a past I haven’t experienced. With each generation, the ripples from the greatest genocide ever known grow a little weaker. But that only makes stronger the feeling of responsibility, to keep alive the memory of what happened in the hope it never happens again. Reclaiming my German nationality felt like one small way to make peace with it.

My brother and I had our appointment at the embassy early in the morning, and I was about to pull on any old thing when I remembered how important it always was for my grandmother to look smart. Nobody could accuse her of being a “dirty Jew” if she looked immaculate. So I wore a cashmere jumper (her favourite wool) and placed my mother’s 1960s necklace on top, so I could take Eva with us, too.

“I present to you, Catherine, your certificate of naturalisation.” I burst into tears. Our grandparents’ and great-grandparents’ names had been put back into the bureaucracy. They existed. They had been wronged, and with this one small gesture, the German government was trying to make things a little more right. We were holding out our hands in forgiveness to shake those of younger Germans, who also bore no responsibility for the past at a time of growing nationalism and suspicion of “the other” in Europe. All of this had contributed to the making of the decision, one many older Jews might find hard to understand. But what I hadn’t expected was the immediate personal sense of completeness I felt. I had grown up fearing Germany. I found the language ugly and chose French, Russian, even Arabic to study so that I wouldn’t have to engage with that “mother” tongue. On the rare occasions when I have visited Germany, I couldn’t help but look at people and wonder what their parents or grandparents had done during the war. But, with German citizenship, I had to accept that I was half German, too, that the darker side I had always tried to deny was an important part of me, just like my cancer is now.

Our daughters and their children can also apply now for dual citizenship, and applications are in for all four of my mother’s granddaughters. There is some small sense of justice, of circularity in the way my mother’s whole family is being welcomed back, even if that is just in spirit when not so very long ago the Nazi regime reduced so many of my family, and millions of others, to dust. Restoring our citizenship is, of course, the least the German state could do, but for me that small gesture feels healing and uniting. I hope that when my daughters’ and nieces’ passports come through, I will still be well enough to travel back to Berlin for a holiday with my family, and have a ball.

• On Smaller Dogs And Larger Life Questions by Kate Figes is published by Virago at £15.99.

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