The collection consists of around eight thousand items of correspondence and more than forty boxes of drafts, notes and other working material, personal and financial documents, press cuttings, many of them annotated, and photographs. The majority of Gerhardie's surviving literary papers date from his most productive period, from the mid-1920s to the late 1930s. His earlier and later work is less well represented. His letters include significant correspondence with fellow writers, in particular Hugh Kingsmill and Morchard Bishop (the pen-name of Oliver Stonor), both of whom wrote frequently to Gerhardie about their own lives and work. Gerhardie also corresponded at length with Katherine Mansfield and Edith Wharton, and photocopies of these letters are in the collection. There is a large set of letters to and from members of the public, prompted by Gerhardie's novels and newspaper articles. A considerable part of his writing and correspondence reflects his interest in paranormal phenomena and ideas about survival after death, and the collection provides an insight into the widespread public interest in these subjects, especially during the 1930s. Gerhardie's correspondence with his family reflects many aspects of recent European history, as his family was dispersed throughout Europe after the Russian Revolution. The First World War in Russia, the Stalinist period, and the Second World War in Britain, France and Russia are well represented in this respect.