The records in WO 400 cover men (NCOs and other ranks) who served in The Household Cavalry between 1799 and 1920, although you will only find records on this British Army Ancestors site for men who were born from the 1830s.
Cavalry duties in the British Army were performed by Household Cavalry and Line Cavalry, and the records in WO 400 only comprise Household Cavalry. Specifically, the regiments concerned are the Royal Horse Guards, 1st Life Guards and 2nd Life Guards; all of these being distinct regiments with their own proud regimental traditions. During the First World War, a fourth regiment, The Household Battalion, was also raised, and the papers found within WO 400 comprise the service records of non-commissioned officers and men who served with all four of these regiments.
The records here are very much complementary to other rank service records in WO 97 and WO 363, and pension records in WO 364 so if you can’t find your household cavalry ancestor in these series, don’t forget to check WO 400.
Contents of the files vary from person to person and whilst some files may only contain two or three images, others offer more detailed pictures of our Household cavalry ancestors. The uniforms of the Household Cavalry regiments were and still are very distinctive, and there is no better site to help you understand this than the Uniformology site. Broadly speaking, the 1st and 2nd Life Guards wear red jackets and sport white plumes on their helmets, whilst the Royal Horse Guards – also known as The Blues and Royals – wear blue jackets and sport red plumes. Armed with this basic information, you are now perfectly placed to impress your friends and family with your knowledge of British household cavalry regiments the next time you watch a ceremonial display on TV.
The Household Cavalry collection in WO 400 comprises surviving records of service for non-commissioned officers and other ranks who served in the Life Guards, the Royal Horse Guards and the Household Battalion, and whose Army service concluded in these regiments. So if your man served with one of the above regiments but then transferred elsewhere his records would have gone with him and you won't find them here.
The WO 400 Household Cavalry collection is a combination of military documents - the common documents found in WO 97 and WO 363 - and Ministry of Pensions correspondence. The documents have been scanned in colour and for the most part the originals appears to have been in good condition. In common with documents in other series however, it is clear that these files have been heavily weeded and so often it is only the attestation paper which remains.
The modern image I have used on this page is courtesy Wikipedia and shows dismounted members of the Royal Horse Guards (left) and Life Guards, preparing to line the route of the procession to St George's Chapel, Windsor Castle for the annual service of the Order of the Garter.