Operational records known as war diaries

All units of the size of an infantry battalion, cavalry regiment, artillery brigade and above were obliged to maintain a record of their movements and activities. These records are called war diaries.


  • Most of the diaries still exist and are held at the National Archives in series WO95. There is a current programme to digitise the diaries and make them available to download (small fee) from the National Archives website
  • The Naval & Military Press offers a DVD that helps access the diaries
  • Ancestry has some diaries
  • Some regimental museums have copies or transcripts
  • A few regiments, museums and individuals have made transcripts available online
  • Canadian and Australian war diaries – including those of British units serving under Canadian or Australian formations – have been digitised and are freely available via the internet.

Contents and value to researchers

The diaries vary in the degree of detail they describe. Most do not mention men of the “other ranks” very much, if at all. Officers are regularly mentioned by name. Some diaries include added operational reports, signals, maps, casualty lists and other documents. They are an exceptional resource for determining the details of the activities of a given unit.

Part of the war diary of 27 Field Ambulance RAMC. National Archives WO95/1758. Crown Copyright.
Part of the war diary of 27 Field Ambulance RAMC. National Archives WO95/1758. Crown Copyright.

The majority of soldiers are not mentioned by name, but the practice varies by diary and by period. Some diarists were diligent in naming every casualty, for example, but at peak times this just becomes “X other ranks wounded”. Gallantry awards are often mentioned. Some diaries also include original lists – and they can be most valuable resources giving information that cannot be found elsewhere.

Diary extract
An extract from the diary of the 4th Battalion of the King’s Royal Rifle Corps. National Archives WO95/2843. Crown Copyright. An example of a casualty list included with the diary: gold dust for a researcher!

If you are trying to understand the movements or locations of a unit, the war diary is your key resource. Sometimes it also pays to see the diary of the formation to which your unit was subordinate (for an infantry battalion this will be a brigade, for example). They tend to include more maps, orders and other useful details but are less likely to mention individuals.