Due to the rapid expansion of the Royal Artillery at the start of and just prior to the start of the war, a number of yeomanry regiments were converted to RA. Also, infantry TA regiments were converted. From 1941 to 1943 Medium Machine Gun units were converted to anti-tank regiments.

All of these appear in their own lists for ease of reference as well as being in the appropriate unit list.

The Royal Horse Artillery
Field Regiments
Medium Regiments
Heavy Regiments
Super Heavy Regiments
Army Groups RA (AGRA’s)
Anti-Tank Regiments
Light Anti-Aircraft/Anti-Tank Regiments
Light Anti-Aircraft Regiments
Heavy Anti-Aircraft Regiments
Anti-Aircraft Z Regiments
Searchlight Regiments
Composite Light Anti-Aircraft /Searchlight Batteries
Moonlight Batteries
Radar Units
Air Defence Great Britain
Coast Artillery Regiments
Light Regiments (incl Parachute & Air Landing units)
Mountain Regiments
Survey Regiments
Maritime RA
Air Observation Post Squadrons Royal Air Force
Defence Regiments
Garrison Regiments RA
Infantry Regiments RA
Officer Cadet Training Units
Schools & Training Establishments
Yeomanry converted to RA
TA infantry converted to RA
MMG Battalions converted to anti-tank regiments RA
Royal Marine Artillery Regiments
Royal Malta Artillery Regiments
Hong Kong Singapore Regiments RA
West African Artillery
East African Artillery