- Main article: List of Surviving Lonsdale Records
The list of Lonsdale Records relating to the Lowther family and the Earls of Lonsdale are stored at the Cumbria Record Office (Carlisle Headquarters). The Lowther Family Estate have thousands of records listed in various categories and sub-categories ranging from DLons/L5 to DLons/L25. The records relating to the 11th Border Regiment (Lonsdale) range from DLons/L13/13/1 to DLons/L13/13/282
D LONS/L13/13/231–232
12th (Reserve) Battalion / Training
- D LONS/L13/13/231: File re training including bayonet fighting, provision of training areas, training courses - date: 15 April - 8 October 1915
- D LONS/L13/13/232: Papers re training including programmes of work, returns of men attending training courses - date: 18 September 1915 - 23 August 1916
—For access to the above records please contact the Cumbria Archive Centre (Carlisle)