When I was growing up in post-Soviet Moscow, no one could answer my questions about being Jewish. My parents had been brought up in an atmosphere of suspicion and paranoia, their families had survived Stalinist purges, and here I was, asking them about Chanukah. By then, in the 90s, it was no longer dangerous to talk about being Jewish, but trauma is a powerful thing, and silence was their only response.

The truth is, they wouldn’t have known what to tell me.

My grandmother, Anna Neyman, was born in 1923, when Lenin had less than a year left to live. As the Bolsheviks established complete control of the country, there was space for only one identity — the communist worker. And so my grandmother, now 97 and living in London, would never learn about the customs and traditions that dominated her father’s childhood in Warsaw.

Anna’s father, Marcus, had come to Moscow to follow his revolutionary dreams of Communism. Arriving during the turbulent years after the Great War, he didn’t change his identifiably Jewish name, but he left his Jewish life behind.

The hints were everywhere, though. “That violinist is Jewish”, my grandmother would whisper conspiratorially as we watched TV in the evening, and so was the eccentric pop singer who seemed to be on every music programme. You could rarely tell that by their names, but my granny always knew.

I also absorbed enough Jewish jokes and folklore from Odessa, of which my mother was a huge fan, to understand that Jews were funny, different, and not always appreciated.

But that was all for the kitchen, a conversation that could sometimes be had quietly, when no one was listening.

In the late 90s, just before we left Russia and came to live in London, I went to a school around the corner from a synagogue. I would often walk past it on my break towards the nearby McDonald’s, sneaking glances towards the old men sitting on the steps out in front. “She’s one of us,” one of them shouted out to me, once, and I hurried off terrified. How did he know that?

Being Jewish wasn’t the only thing we talked about behind closed doors. There were also the photographs of glamorous women and men that my grandmother would get out when nostalgia struck, and reminisce. Kept in an old yellow plastic file, the faded black-and-white images had a barely legible scrawl on the back. Anna had treasured them since she was a little girl, receiving news of her cousins in Switzerland. She couldn’t tell me any more than their names and that they lived in Geneva.

The admiration in her voice when she talked of her uncle Adolphe, her father’s brother, was remarkable. He must have been a great man I thought, not realising that choosing to go west when he left Warsaw instead of east, warranted great respect in her eyes. But what happened to my grandmother’s cousins, and where were they now?

Adolphe went to Switzerland in 1905. There, he found a job and started a family, eventually becoming a successful watch factory owner in Geneva. This information was definitely dangerous in the Soviet years. But now that I had it, I was desperate to know more.

The magnetic appeal of everything Jewish continued. I was incensed when, upon receiving my first internal passport at the age of 14, I was not allowed to change my Russian surname for my father’s obviously Jewish name — Landsman. I thought it would suit me better, but for once, my grandmother spoke up, reminding my parents that her generation had been through too much to give up a Russian name so easily. My rebellion was extinguished before it really began.

I wanted to know about the huge menorah I had seen mounted on top of a white limo crossing one of Moscow’s bridges — yes, the ostentatiousness of post-Soviet Russia applied to some in the Jewish community as well. But what was Chanukah about? No one in my family knew.

All I had were some Jewish surnames in our family tree and rumours of glamour and wealth in Geneva.

It took me another decade after moving to London to start searching for my Swiss family. In those ten years I went to university, joined JSoc, made Jewish friends and spent a lot of time questioning them about Jewish history and traditions. I finally learnt about Chanukah, and went to my first candle lighting at a friend’s house. I sat starving through my first Seder, wondering when the haggadah was going to finally end, as my stomach rumbled at the most delicious smells coming from the kitchen. And I went on Birthright to Israel, exploring the Holy Land in depth and detail. There was just one piece that was still missing. And so, by the time a genealogy website threw up the names of my cousins once and twice removed, I was ready.

The website, geni.com, will be familiar to those who enjoy putting together family trees and looking for lost relatives. I already had the core of my family tree built for me by my uncle on my father’s side — my mother and I were admiring all the hard work he had put in to build his side of the huge family tree, with relatives and roots spreading out from Kazakhstan to Latvia. Now it was our turn, my mother and I agreed, as we started putting names into the search bar, hoping for a result.

It barely took an hour. One meagre hour to find members of my family we had thought lost for 60 years. An hour for my mother to see the names she had learnt as a little girl, the names she had learnt never to utter outside the house, in front of her, in black and white.

Sixty years since contact between the two branches of my family had been lost, I clicked “send” on my first message to one of Adolphe’s granddaughters. Did they know about us? Would they believe we were who we said we were? There was only one way to find out. I was hoping that she would reply, and acknowledge our existence. We had known about her family our whole lives, and a rejection would have been devastating.

I needn’t have worried. With the overjoyed and astonished reply, messages started flowing in. Adolphe’s youngest daughter, Genia, was still alive, approaching her 97th birthday. With my grandmother only a decade younger, we started planning our first meeting. We spent six months preparing. My grandmother, looking over her precious archive of photographs and trying to conjure up lost memories of her father. My mother, sourcing Russian souvenirs from Moscow to bring to Geneva. And I, trying to work out what secrets our family tree held and what it would be like meeting our newly found family for the first time.

And then, we were finally in Geneva. Anna and Genia had years of lost time to make up for. How do you get to know somebody you’ve known about your whole life but have never met? Do you start with their marriage, or their best years? For Anna and Genia, there were whole decades to talk through. For a while the conversation lingered in the air, as the cousins were unable to take the plunge and settle on the most important, the most interesting or the most urgent. We learnt about Genia’s life in Palestine before the outbreak of the Second World War. Her sister’s years in occupied Belgium were mentioned too. She was lucky to have escaped, returning to her parents in Geneva. It was history I had learnt about on the pages of my old school books, but suddenly I could see it was the story of our family, too.

Looking around the room and feeling the warmth and excitement of our reunion, there was no doubt in my mind that we were one family. It was astonishing to see how one fateful decision brought about such contrasting experiences for the two brothers, and how their descendants’ lives were impacted by their choices. My great-granduncle Adolphe, his features strikingly similar to those of his brother Marcus, watched over us from a portrait in a frame of old lacquered wood, as we celebrated this new chapter of our family history.

Being with her cousin for the first time, my grandmother thought of her favourite poem by the German poet Heinrich Heine, and she recited the German words she had treasured since she first learnt them as a schoolgirl in Moscow.

I do not know what it might bode

That I should be so sad,

A fairy tale from long ago

Now will not leave my head.

Suddenly, Genia started singing the same words, the lyricism of the writing reinforced by the melody of the song. Her now fragile voice added to the sadness of the poem. Anna’s eyes glistened with tears as she clasped her hands, laughing.

As I describe in my book, after our first meeting I spent years going back to Switzerland — but also to Belgium, Poland and Israel, as I tried to piece together the stories of our family which had been hidden for generations.

In the past decade I have felt richer and more rooted in my history and identity than I thought possible. Knowing where your family comes from, where your great-great-grandparents are buried or what happened to your ancestors on their journeys, is a privilege not to be taken for granted. I grew up wanting to know more about the women and men in the photographs. Now, I have written a book about them, so that my children and grandchildren will always know where they came from and what happened to their family in the twentieth century. This is what we mean when we talk about family.

Worlds Apart: The Journeys of My Jewish Family in Twentieth-Century Europe is published by SilverWood