I was walking along a back street, Luisenstraße, in the little German town of Wuppertal on a bright spring morning when I first stumbled, as the artist intended, upon an example of a Stolperstein, which literally translates as “stumbling stone”.

The expression metaphorically refers to a “stumbling block” – one of Gunter Demnig’s many brass pavement setts installed across Europe to commemorate victims of the Holocaust, memorialised at their last freely chosen place of residence. 

Here are four together, stating simply “Hier wohnte…” [Here lived…] Emil and Henriette Hirschberg, ermordet [murdered] in Minsk, and Samuel and Sophie Zuckermann, ermordet respectively in Chelmno and Auschwitz.  There are now over seventy thousand of these poignant reminders, deliberately designed to trip up the unthinking passer-by, from Spain to Greece and from Poland to Sicily. 

There were two outside my 1950s Berlin hotel in the heavily bombed area of Friedrichshain, and I found another on a pavement in the modern development that replaces the bombed wastes of Potsdamer Platz, where the course of the Berlin Wall created a dead zone that lasted a generation after the war ended.

I spotted another, in Budapest, embedded in the pavement of what had been the Jewish Quarter but which became, at the end of 1944, the ghetto.  Here the last fragment of the ghetto wall was dismantled in 2006 but a reproduction, using some original stone, was erected as a memorial two years later.

Gunter Demnig’s work is much less likely to be obliterated, even if a few setts are discarded, and there can never be too many reminders of the mass murders of 1933-45.

It’s idle to believe that such a crime could never happen again.

I carry with me the last line of Bertholt Brecht’s 1941 play, The Resistible Rise of Arturo Ui:  “The bitch that bore him is in heat again.”