My parents had lived through the Second World War and their families were affected by both wars; loved ones lost, relationships fractured. My mother was a Londoner and had lived through the Blitz as a teenager with her mother. She had two older brothers who were away in the navy and her father who had fought in the First World War was a steward on British Rail. My father had been on his way to Burma when it fell to the Japanese; he was redirected to India and never saw any action. My parents met and married soon after the end of the war and my sister and I were born in 1947 and 1949 respectively.

I never met any of my grandparents; three of them were dead and my mother lost contact with her father after a falling out when he remarried; well, that’s what she told us. We once visited one of Mother’s older brothers and his family but that was the only occasion I remember; the other brother had emigrated after the war and was living in America. One by one she cut ties with her family. Years later her brother in America wrote to her but she didn’t reply. I didn’t think any of this was strange and just assumed that the war had caused the fragmentation of a lot of similar families.

My mother lived into her nineties and we got her to move to a bungalow a few doors from us so we could be close at hand and I went to see her every day. It was through these chats I formed the impression there was a skeleton somewhere in those family cupboards; nothing particularly concrete just moments when she subtly changed the subject or seemed to be evading something. She died in 2016 and I suspect she believed she was taking the secret with her.

I had dabbled into my family’s ancestry but mainly on my father’s side. It was my son, Alex, who took the baton from me and did some further digging and even went as far as sending off a sample of his DNA.  He hoped to find something a bit exotic and exciting in his search and was disappointed when it came back that he was 55 per cent English, 32 per cent Scandinavian and 13 per cent Celtic. He didn’t need to wait long before his wish was answered but not in the way he expected. He lives in the Netherlands and so the conversation took place one day via texts. ‘Your mother,’ he wrote, ‘had four brothers: Alfred, Victor, Terence and Ronald. Terence died young and Ronald was born in 1929 four years after your mother ’

I texted back: ‘Mother only had two older brothers, are you sure you are not on the wrong branch of the family tree. She never mentioned a younger brother.’

Another text came back: ‘Ronald was an actor and carpenter.’

With it was a photograph. I laughed out loud and texted back: ‘don’t be daft that’s Ronnie Biggs the great train robber. I got a text back: ‘Are you serious?’

Ronnie Biggs had been one of the gang that had held up a mail train in 1963 and stolen 2.6 million pounds; the biggest robbery in history at that time and when most of the gang were arrested it made news headlines around the world so his face was familiar to me but not necessarily to my son. It had been a family joke that Mother shared her maiden name with a notorious criminal but she explained it away as a co-incidence and we never questioned it again.

Alex was indeed right, Ronnie Biggs was my uncle. That last piece of the jigsaw puzzle had fallen into place; the younger brother who was evacuated during the war, the black sheep of the family in trouble with the law for minor offences and then national infamy in 1963. He became even more well-known after his escape from prison in 1965 and his subsequent escapades around the world avoiding capture. Was the secret kept as a desperate attempt on my mother’s part at respectability? Did she think it would affect our father’s career or have a negative effect on her children? Whatever the reason she kept the secret well.

Perhaps it could have had a positive effect in that I might have avoided some of the bullying at school when other boys said something along the lines of: ‘my dad’s tougher than your dad’ I could have topped that with: ‘Yeah, but my uncle is Ronnie Biggs.’