On 21 September 1941, a group of 400 women from Lublin and Warsaw was taken to Ravensbrück, the notorious concentration camp for women near Berlin.

As TFN’s history notable Stuart Dowell tells this week’s The Debrief, the group included four Girl Guides who had been arrested for involvement with the Polish Underground. They would go on to create the secret letter writing group.

Read the full story here.