Preprinted acknowledgment postcards sent by return by prisoners-of-war in German camps on receipt of relief parcels organised by the Birr Castle scheme. Personal details recorded include name, rank and internment camp.

Eleven letters from Constance Plunkett-Johnston to her mother Maria Blanche Plunkett-Johnston at Rockfield, Moate, County Westmeath. Constance was traveling to Germany with her cousin, Eva Marsh (later Monteith), and described their trip in great detail. Her letters are sent from the Euston Hotel, London, England; the Lord Warden Hotel, Dover, England; the Hotel De Flandre, Brussels, Belgium; the Grand Hotel, Homburg, Germany; Morley's Hotel, Trafalgar Square, London, England; and Mount Jerome, Harold's Cross, Dublin, Ireland.

Letter and transcription of a german letter sent in response of an inquiry into the Cronhelm family history in Germany, from Joseph Rilland Crusott to Mister Cronhelm, regarding hi investigation into the family of Cronhelm in Hanover.

Photograph album created by Lt. Col. M. O'Carroll Fitz-Simon, M.C. , who began his military career in Prince of Wales' Leinster Regiment, which was headquartered at Birr. The photographs document a peace-keeping mission the Leinsters undertook in Silesia (now part of Poland) from their departure at Dover on 31 May 1921, through Germany and to their destination of Oppeln (Opole in Poland today). Following the disbandment of the regiment in June 1922, Fitz-Simon joined the King's Own Regiment, Lancaster and the remaining photographs in the album depict scenes from missions in India and Burma. There is also a small number of photographs of people and houses in the Birr area including Whigsborough House, and the burnt out remains of Birr Barracks (following its destruction in the Civil War in July 1922).