This collection consists largely of letters from Roger Casement to Captain Hans Boehm, during Casement's stay in Germany in 1915, as well as some associated material (photographs, medals) relating to his first contact with the German authorities in November and December 1914 and the formation of the Irish Brigade in 1915.

[Postcards of Limburg and a photograph of the prison camp.]

File contains confidential Admiralty Memoranda re: 'Instructions regarding Hostile Submarines' ; 'Submarines in Home Waters' ; 'Instructions regarding Use of Rifles and Machine Guns by Merchant Vessels for Defence against Aircraft and Submarines' ; 'A Suggestion for rendering ships of the Mercantile Marine immune from the effects of torpedo attack' ; profiles of British and German Submarines ; list of Irish Lights Stations electrically connected with Telegraph Service.