How to look for records of... Military and maritime records: an overview

How can I view the records covered in this guide?

How many are online?

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In this guide we provide a brief overview of military and Merchant Navy records held at The National Archives. We will help you to understand some of the basic principles of searching for these records and to decide where on our website to go next. There are links throughout this guide to our more in-depth research guides where you can find more detailed advice on how to search for specific types of military and maritime records.

What are these records?

Military and maritime records at The National Archives are records once held by central government departments, especially the departments responsible for the British Army, the Royal Navy, the Merchant Navy and the Royal Air Force. Among them are records of service for individuals, operational plans and reports, administrative records of various kinds all the way up to those documenting top level government policy and decision making. These are the original records, most of them paper records, that played some part in the working life of these departments and the branches of the military which they governed. In some cases there are online versions, most commonly for records of individuals, but in many cases there are not.

How to get a search for records started

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.

How to view records

Each guide will indicate whether some or all of the records in question have been made available online (charges usually apply). The online copies are accessed either directly from our website or from the websites of our licensed partners, including Ancestry and Findmypast (charges apply). To see records that have no online versions you will need to pay for copies to be made and sent to you or visit our building in Kew, where you can consult original records without charge and make your own copies with your own camera.

As well as a short description of its subject matter, each catalogue entry comes with a document reference (also referred to as a catalogue reference) and details of how you can view the record. If there is no online copy, you will need the document reference to see the record itself or to request copies.

Records of individuals


Military service records are held separately for each branch of the military and records of officers are separate from other ranks. The records themselves vary in the detail they contain, from a full service history, to attestation papers or discharge papers, or entries in a list or register. This is explained in more detail in the research guides.

Records of military service after the First World War, including those for service in the Second World War, are just beginning to be transferred from the Ministry of Defence to The National Archives. For general advice, for all services, see our guide to soldiers in service after 1918.

There are guides for:

For records of women’s military or other wartime service, see our guides to

Merchant Navy

Records of service in the Merchant Navy are more varied. A number of different sorts of record were used by the Board of Trade to record the voyages of seamen and qualifications of officers. Our guidance therefore covers different date ranges but there may still be several different types of record for each individual seaman within each date range.

For records of passengers on merchant ships consult our guide to Passengers.

Records of ships, squadrons, battalions and other military units

In general, for information on specific units of the military you need to look in ‘operational’ records. They take the shape of logs, record books and diaries recording the activities of air force squadrons, Royal Navy ships and British Army units. As well as containing details of the operations and activities themselves, they can provide background information to supplement service records or, if individual records are not available, fill in for them. The following guides are available for military operational records:

Pre-First World War First World War Second World War Post 1945
Royal Navy Royal Navy operations and correspondence 1660-1914 Royal Navy operations in the First World War Royal Navy operations in the Second World War Royal Navy operations and policy after 1945
Army British Army operations up to 1913 British Army operations in the First World War British Army operations in the Second World War British Army operations after 1945
Royal Air Force Royal Air Force operations

For records of movements of merchant vessels consult our guides to

Our guide to Ships wrecked or sunk has advice on finding records of shipwrecks and losses of both merchant and naval vessels.

We have incomplete collections of Lloyd’s Register of Ships and the Mercantile Nay List in our reading room.

Also see our guide to Maritime history records held by other archives for information on other archives holding significant collections related to merchant shipping, including the records of shipping companies.

Records of battles and military operations

See the table in the previous section for links to guides with detailed advice on operational records. However, in general, to search for records of the planning of military operations, battles or conflicts, and reports on their outcomes, you can search the catalogue using the name of the battle or the codename of the operation. Alternatively, search with the place or country where the battle or operation took place coupled with terms such as ‘war’, ‘battle’, or, for some 20th century records, ‘conflict’ or ’emergency’, along with appropriate date ranges.

It is usually worth trying alternative search terms, even if the initial search appears successful. In some cases, terminology may have changed since the time the records were created or may not be consistent across all related records. For example, a search for records on the ‘Opium Wars’ using the keywords ‘opium’ and ‘war’ for records from 1839-1860 finds mainly Foreign Office records but no War Office documents. However, related War Office records and more Foreign Office records are found with a catalogue search across the same range of years but using ‘China’ and ‘war’ as keywords (in both instances, note the ‘Collection’ filter on the left hand side of the page for a breakdown of the departments containing matching records).

Consult our overview guides for wars for further guidance on researching records of particular conflicts.

Research and development

For advice on finding records of military research and development, covering weapons technology, military hardware and so on, consult the guides below:

Government policy and administrative records

Worthwhile search strategies for finding records of high level government policy or discussions touching on the military and Merchant Navy include general searches across our catalogue, using a single or a couple of broad keywords as search terms, such as ‘nuclear policy’ or ‘peacekeeping’, and restricting results to specific years ranges or dates. For detailed guidance on records from the early 20th century onwards, see our guides to:

For advice on searching for earlier records see the various guides under our political history (general) index tag.

For the impact of government policy in the British Empire and Commonwealth and in the rest of the world, read our guides to:

As well as the main government ministries overseeing the Merchant Navy and armed forces, many other government departments may have had a stake in government policy and administration and hold relevant records. For example, this search for collections of records related to ‘shipbuilding’ shows wide ranging Government involvement across over a dozen departments.

Further reading

The following publications and many more are available through our library or bookshop

Amanda Bevan, Tracing your Ancestors in The National Archives (The National Archives, 2006)

William Spencer, Army Records: A guide for family historians (The National Archives, 2008)

William Spencer, Records of the Militia and Volunteer Forces 1757-1945 (Public Record Office, 1997)

Bruno Pappalardo, Tracing Your Naval Ancestors (The National Archives, 2003)

N A M Rodger, Naval Records for Genealogists (Public Record Office, 1998)

Bruno Pappalardo, Using navy records (Public Record Office, 2001)

William Spencer, Air Force records for family historians (The National Archives, 2008)

Christopher and Michael Watts, My Ancestor was a Merchant Seaman (Society of Genealogists, 2002)

Kelvin Smith, Christopher Watts, Michael Watts, Records of merchant shipping and seamen (Public Record Office, 2001)