Before you begin a search you should see if there is a guide to the specific type of records you are looking for – this guide is designed to help you to do that. In the sections below you will find links to guides on specific categories of military and maritime records. We list only the main sources available in each category but you can also look through a list of all our military and maritime guides. To search for records, except for those provided online by our licensed partners, you will usually need to use our online catalogue. The catalogue contains short descriptions of the records and a search in our catalogue means searching for the keywords and dates that match these short descriptions. Some descriptions are just a word or two, essentially the titles of the original files, others contain several sentences of descriptive text. The more you get used to the format that these descriptions take, the more successful your searching is likely to be.
Our guides provide suggestions for keywords you can use to find different record types as well as guidance on some of the departments and series you should target in your search. The records are arranged by the government departments that created them, each one identified by a National Archives department code. Five of the most significant departments for these records are:
- The War Office, which administered the British Army – department code WO
- The Admiralty, which administered the Royal Navy – department code ADM
- The Air Ministry, which administered the Royal Air Force – department code AIR
- The Ministry of Defence, which replaced these three departments and brought the branches of the military together under one umbrella department – department code DEFE
- The Board of Trade, the parent government department for the Registrar General of Shipping and Seamen which administered the Merchant Navy – department code BT
Each of these departments is split into a large number of series which can be searched individually. A series contains records grouped together and usually linked in some way. A series is distinguished by its own reference, consisting of two parts: the first part is the department code, the second part is the series number. For example, British Army unit war diaries for the First World War form a single series, with the catalogue reference WO 95 – click on this reference to search the series.
A document within a series will have one or two further elements to its reference. For example, the unit war diary for the 10 Battalion Argyll & Sutherland Highlanders, May 1915 to April 1916, has the reference WO 95/1772/1.