Eighty years on from the day Soviet troops arrived at the Auschwitz-Birkenau concentration camp, survivors, international heads of state and dignitaries gathered at the site in Poland where more than 1 million people, mostly Jews, were murdered. International Holocaust Remembrance Day is marked around the world on 27 January

• Auschwitz anniversary – live updates

Revisited: Ivor Perl and Susan Pollack were 12 and 13 when they were transported to Auschwitz. On the 80th anniversary of the concentration camp’s liberation, we revisit a podcast we published marking the 75th anniversary

This episode was first broadcast on 27 January 2020 to mark the 75th anniversary of the liberation of Auschwitz.

On 27 January 1945, Soviet soldiers entered the gates of the Auschwitz concentration camp in south-west Poland. The site had been evacuated by the Nazis just days earlier. Thus ended the largest mass murder in a single location in human history.