The collection includes letters from Karl Marx, requesting UK citizenship; an anonymous writer purporting to be Jack the Ripper; Josef Kramer, the commandant of Bergen Belsen; Winston Churchill to President Roosevelt, requesting US support against Hitler; Clement Atlee to Harry S Truman following Hiroshima; the spies Burgess and Maclean; as well as the ‘real Charlotte Gray’ spy, Christine Granville, amongst others.

Topics covered include the Monteagle letter that warned about the Gunpowder plot, letters from the Wright brothers trying to get the War Office to fund their aeronautical research, a dispatch on the murder of Archduke Franz Ferdinand, Christine Keeler’s Russian-British love triangle that begat the Profumo affair, US disapproval of British trade with Cuba, a letter reporting on the first day of the trial of Nelson Mandela and the anonymous letter that framed the Krays.