So much of your daily life – your job, your health, your home – hinges on the fact that your name is in a government database. Are you a legal citizen of your country, with everything that entails? You are, until an anonymous bureaucrat hits a key one night and strips it all away, turning you into an illegal immigrant. It happened in Slovenia in 1992.

“I took my son to register for secondary school. The clerk rifled through the papers, then stared at me as if refusing to see the boy standing right next to me. Finally, she said: ‘But you don’t have a son. He doesn’t exist.’” I can’t forget the look on the face of the woman who was telling me this story. It was a mixture of deep hurt and bewilderment, with a pause after every sentence, as if she were walking through a minefield. During the research for my book Erased, I compiled countless stories like this: stories I once would have thought impossible.

On 26 February 1992, the Slovenian government quietly deleted 1.3% of its citizenry overnight. The criterion was frighteningly simple: anyone born in another part of the former Yugoslavia who was a permanent resident of Slovenia (regardless of whether they considered themselves naturalised) suddenly lost their citizenship, their right to reside, their healthcare, their pension: everything. They were transformed into illegal immigrants overnight, without prior notification, and with no right to appeal. The goal was to cleanse Slovenia of a Balkan “fifth column” and pivot closer to Europe.

I have long felt this dark piece of........

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