The London Guards is a formation within the British Army comprising the reserve companies of the Grenadier, Coldstream, Scots and Irish Guards. On formation these companies drew their personnel from the London Regiment and it traces its history back to the formation of that regiment in 1908 when 26 separate Volunteer Force battalions were brought together. The London Guards is not a regiment, the companies wear the uniform, and follow the traditions, of their foot guards regiment.

The Army Reserve is the active-duty volunteer reserve force of the British Army. It is separate from the Regular Reserve whose members are ex-Regular personnel who retain a statutory liability for service. The Army Reserve was known as the Territorial Force from 1908 to 1921, the Territorial Army (TA) from 1921 to 1967, the Territorial and Army Volunteer Reserve (TAVR) from 1967 to 1979, and again the Territorial Army (TA) from 1979 to 2014.