
The Machine Gun Corps (MGC) was a corps of the British Army, formed in October 1915 in response to the need for more effective use of machine guns on the Western Front in the First World War. The Heavy Branch of the MGC was the first to use tanks in combat and was subsequently turned into the Tank Corps, later called the Royal Tank Regiment. The MGC remained in existence after the war until it was disbanded in 1922.

The Scottish Horse was a Yeomanry regiment of the British Army's Territorial Army raised in 1900 for service in the Second Boer War. It saw heavy fighting in both the First World War, as the 13th Battalion, Black Watch, and in the Second World War, as part of the Royal Artillery. It amalgamated with the Fife and Forfar Yeomanry to form the Fife and Forfar Yeomanry/Scottish Horse in 1956. The lineage is maintained by "C" Fife and Forfar Yeomanry/Scottish Horse Squadron of The Scottish and North Irish Yeomanry based in Cupar in Fife.
The Lincolnshire Yeomanry was a volunteer cavalry unit of the British Army formed in 1794. It saw action in the Second Boer War and the First World War before being disbanded in 1920.

The City of London Yeomanry was a yeomanry regiment of the British Territorial Army, formed in 1901 from veterans of the Second Boer War. In World War I it served dismounted in the Gallipoli Campaign but reverted to the mounted role in the Senussi campaign, at Salonika and in Palestine. It ended the war as a machine gun unit on the Western Front. In the interwar years it was reduced to a battery in a composite Royal Horse Artillery unit in London, but in the period of rearmament before World War II it was expanded into a full regiment of light anti-aircraft artillery. It served in this role during The Blitz and later in the Tunisian and Italian campaigns. Postwar it became an armoured regiment. It amalgamated with the Inns of Court Regiment to form the Inns of Court & City Yeomanry in 1961. The lineage is maintained by 68 Signal Squadron, part of 71 (Yeomanry) Signal Regiment.

The Westminster Dragoons (WDs) was a yeomanry regiment of the British Army Army Reserve, located in central London. Its lineage is continued by one of the Royal Yeomanry's six squadrons. Formed in the aftermath of Second Boer War as part of the County of London Yeomanry, the WDs fought in the Battle of Gallipoli and led British forces onto the beaches during the Normandy Invasion in 1944. The squadron most recently saw action on Operation Telic, for which it was mobilised for the 2003 war in Iraq.
The Lincolnshire Yeomanry was a volunteer cavalry unit of the British Army formed in 1794. It saw action in the Second Boer War and the First World War before being disbanded in 1920.

The City of London Yeomanry was a yeomanry regiment of the British Territorial Army, formed in 1901 from veterans of the Second Boer War. In World War I it served dismounted in the Gallipoli Campaign but reverted to the mounted role in the Senussi campaign, at Salonika and in Palestine. It ended the war as a machine gun unit on the Western Front. In the interwar years it was reduced to a battery in a composite Royal Horse Artillery unit in London, but in the period of rearmament before World War II it was expanded into a full regiment of light anti-aircraft artillery. It served in this role during The Blitz and later in the Tunisian and Italian campaigns. Postwar it became an armoured regiment. It amalgamated with the Inns of Court Regiment to form the Inns of Court & City Yeomanry in 1961. The lineage is maintained by 68 Signal Squadron, part of 71 (Yeomanry) Signal Regiment.

The Westminster Dragoons (WDs) was a yeomanry regiment of the British Army Army Reserve, located in central London. Its lineage is continued by one of the Royal Yeomanry's six squadrons. Formed in the aftermath of Second Boer War as part of the County of London Yeomanry, the WDs fought in the Battle of Gallipoli and led British forces onto the beaches during the Normandy Invasion in 1944. The squadron most recently saw action on Operation Telic, for which it was mobilised for the 2003 war in Iraq.

The Machine Gun Corps Memorial, also known as The Boy David, is a memorial to the casualties of the Machine Gun Corps in the First World War. It is located on the north side of the traffic island at Hyde Park Corner in London, near the Wellington Arch, an Equestrian statue of the Duke of Wellington, the Royal Artillery Memorial, the New Zealand War Memorial, and the Australian War Memorial.

The Motor Machine Gun Service (MMGS) was a unit of the British Army in the First World War, consisting of batteries of motorcycle/sidecar combinations carrying Vickers machine guns. It was formed in 1914 and incorporated into the Machine Gun Corps in October 1915 as the Machine Gun Corps (Motors).