I suppose it's not surprising, if you embark on a journey in search of your family roots, that you end up visiting a lot of cemeteries. That is, after all, where you're most likely to find your forebears.

So here I am, in the grandest cemetery of them all - the Weissensee, in the eastern suburbs of Berlin, a 20-minute tram ride from the centre of town.

Weissensee is the largest Jewish cemetery in Europe, covering more than 100 acres and containing more than 110,000 graves. Among them, those of my great-grandparents and my great-great-grandparents.

They couldn't be easier to find. Hand in the details at the office, a few clicks of a computer mouse, and the precise plot numbers and locations are identified. A helpful map is provided, with a dotted line along the footpaths to show how to find the right plots.

On my way along the immaculately swept paths, I pass soaring family mausoleums that would make a Medici or a Bourbon proud. They don't reflect the unadorned simplicity of most Jewish cemeteries. But these are the last resting places of Berliners who were as much German as they were Jewish - and it shows.

My great-grandfather Theodor Lustig (1837-1906) shares his more modest spot with his life-long friend David Hesse. They married two sisters, Pauline and Franziska Cohn (not related to my mother's family, who were also called Cohn), who are each buried with them.

Theodor was a modestly successful businessman who would much preferred to have been a doctor. He wasn't a practising Jew, unlike his much more devout father-in-law Victor Cohn (1803-1896).

Theodor's son, my grandfather Franz, was even less Jewish, and he and my grandmother decided to have their children baptised as Lutherans. My aunt wrote many years later: "They believed… their children would no longer be considered Jews, which was always a handicap in Germany. Hitler taught them otherwise."

Indeed, he did. My father and his three elder siblings managed to get out of Germany in the years following Hitler's rise to power in 1933. My grandparents didn't escape until April 1940, when they left Germany by train for Italy and took a boat to Portugal to spend the rest of the war there with their daughter.

But back to the cemetery and my great-great-grandfather Victor Cohn. He and his wife Amelie ran a leather business - he shares his plot here with her, and with two of his four daughters, Therese and Jenny.

The only picture I have of him shows him to have been round-faced, with a high forehead and slicked-back hair. I'm afraid I don't think we would have got on.

On this journey I have visited the grim Ninth Fort at Kaunas, Lithuania where my grandmother Ilse Cohn was murdered by the SS. In Wrocław, formerly Breslau, I found my grandfather's grave, hidden beneath 70 years' growth of ivy. So many cemeteries, but thank goodness, not all the stories are sad ones.

My mother's family story was sadder than most, but when she came to write down her memories of her life, she called them Born under a lucky star. I asked her why.

"I was lucky to be born with an optimistic disposition," she wrote. "It helps when things go wrong."

Robin Lustig is a journalist and broadcaster. More about his project 'In the Footsteps of Our Families' can be found at www.wanderingscribes.com