1908 
 Honourable Artillery Company of the Territorial Force 
 
 Boer War 
  South Africa 1900-02  
 
[designated as: 1st and 2nd City of London Horse Artillery (Honourable Artillery Company), but these titles never used in practice]; each battery also had a mounted ammunition Brigade column
 
 Honourable Artillery Company Infantry Battalion 
 
[designated as: 26th (City of London) Battalion, The London Regiment, but this title never used]
 
with  1, 2, 3 and  4 Company and a machine gun section
 
 1911 
 1, 2, 3 and  4 Company, Honourable Artillery Company Infantry Battalion
 
 A, B, C and  D Company, Honourable Artillery Company Infantry Battalion
 
 1914-18 
Seven batteries of artillery (five operational and two reserve) and three Battalions of infantry (two operational and one reserve) formed:
 
 A Battery and  B Battery reformed in August 1914; went overseas in April 1915 and served separately and together with various mounted infantry Brigades in Egypt, Aden and Palestine
 
 A Reserve Battery and  B Reserve Battery  formed in September 1914; renamed:
 
 2/A Battery and  2/B Battery in February 1915; from June 1917 served with 126th Army Field Artillery Brigade in France and Flanders
 
 309th (Honourable Artillery Company) Siege Battery, Royal Garrison Artillery raised in November 1916; from April 1917 served in France and Flanders
 
 3/A Battery  and  3/B Battery, both reserve batteries, raised in 1914; in 1915 formed part of No. 8 Royal Horse Artillery (Territorial Force) Training Brigade; became:
 
 Reserve Battery, Honourable Artillery Company  in October 1916; in Leeds from February 1917 as independent reinforcement unit
 
Additional  Anti-Aircraft Battery established at London HQ end of 1915 until 1917
 
 1st Battalion, Honourable Artillery Company (also called 1st / 1st Battalion) served in France from September 1914; with Royal Naval Division in France and Flanders from 1915
 
 2nd Battalion, Honourable Artillery Company  (also called 1st / 2nd Battalion) formed in September 1914; went overseas in October 1916 and served in France and Flanders; in Italy from 1917 and later Austria
 
 3rd Battalion, Honourable Artillery Company (also called 1st / 3rd Battalion) formed as reserve Battalion in December 1914
 
 1st Cadet Battalion, Honourable Artillery Company formed in 1916
 
 The Great War 
Battle Honours awarded to Honourable Artillery Company:
 
  Ypres 1915, '17, Somme 1916, '17,   Ancre Heights,    Ancre 1916, Arras 1917, '18,   Scarpe   1917, '18, Arleux,   Bullecourt,   Pilckem, Polygon Wood, Broodseinde, Poelcappelle,    Passchendaele,   Amiens, Albert 1918, Bapaume 1918, Drocourt-Quéant, Hindenburg Line,   Epéhy, St Quentin Canal, Cambrai 1918, Selle, Sambre,    France and Flanders 1914-18,    Piave, Vittorio Veneto, Italy 1917-18, Rafah, Egypt 1915-17,    Gaza,    El Mughar,    Jerusalem,    Jordan, Megiddo, Sharon, Damascus, Palestine 1917, '18, Aden 
 
 1919 
All artillery batteries and infantry Battalions disbanded
 
 Metropolitan Special Constabulary (Honourable Artillery Company Division) 
 
formed and re-designated in 1946 as:
 
 Honourable Artillery Company Detachment, Metropolitan Special Constabulary (G 
 
 Division);  from 1958 administered as part of Regular [Police] Force; re-designated in 2003
 
 Honourable Artillery Company Detachment, Special Constabulary (City of London 
 
 1920 
Honourable Artillery Company re-constituted and re-designated as:
 
 Honourable Artillery Company (Territorial Army);  organised as:
 
 A Battery and B Battery, 11th (Honourable Artillery Company and City of London 
 
 Yeomanry Brigade), Royal Horse Artillery 
 
C Battery coming from City of London Yeomanry (Rough Riders)
 
 Honourable Artillery Company Infantry Battalion with 1, 2, 3 and 4 Company
 
 Honourable Artillery Company Cadet Battalion reformed for a period (later disbanded)
 
 1921 
C Battery re-designated as:
 
 No. 1 Battery (expanded and transferred by 1938)
 
 1925 
 Company of Pikemen & Musketeers formed for ceremonial duties (received a Royal
 
Warrant in 1955 and a Royal Standard in 1987)
 
 1934 
Additional Honourable Artillery Company Unit of Royal Defence Corps raised
 
 1936 
Honourable Artillery Company Unit of Royal Defence Corps replaced by:
 
 Honourable Artillery Company Companies of National Defence Corps 
 
 1938 
Honourable Artillery Company reorganised as:
 
 11th Royal Horse Artillery Regiment (Honourable Artillery Company) 
 
(drawn from:  Headquarters, A Battery and B Battery )
 
 12th Royal Horse Artillery Regiment (Honourable Artillery Company) 
 
(formed with:  C Battery and D Battery) 
 
 Honourable Artillery Company Infantry Battalion with  1, 2, 3 and  4 Company and
 
 1939 
Additional  Honourable Artillery Company Companies formed within  13th (Home Defence) 
 
 Battalion, The Royal Fusiliers in November 1939
 
 1940-45 
Honourable Artillery Company reorganised as:
 
 11th Royal Horse Artillery Regiment (Honourable Artillery Company) with  A, B and  E 
 
 Battery in November 1940; 
 E Battery reduced to a troop in 1942 and combined for a timewith 
 I Battery  but resumed 
 E Battery status in August 1942; 
 239 Battery joined from 76
th Anti-Tank Regiment between March and December 1942; Regiment served in North Africa from December 1941, later in Tunisia, Sicily and Italy
and:  12th Royal Horse Artillery Regiment (Honourable Artillery Company) with  C, D and  F Battery in November 1940; served in North Africa from late 1942, later in Tunisia and Italy;
amalgamated with  11th Royal Horse Artillery Regiment (Honourable Artillery Company)  in September 1945 and:  13th Royal Horse Artillery Regiment (Honourable Artillery Company) with  G, H and
 I Battery in December 1940;  I Battery joined  E Battery for a time in 1942; served in Normandy from June 1944, later Belgium and Germany; disbanded 1947
and:  121st (Honourable Artillery Company) Officer Cadet Training Unit formed in September 1939 within 11th Royal Horse Artillery Regiment (Honourable Artillery Company)
and:  86th (Honourable Artillery Company) Anti-Aircraft Regiment, Royal Artillery formed in August 1939, initially as an officer training unit and re-designated in June 1940 as:
 86th (Honourable Artillery Company) Heavy Anti-Aircraft Regiment, Royal Artillery  with  273, 274 and  275 Battery ;  383 Battery added in February 1941;  341 Battery joined in December 1940 for a few weeks;  446 Battery added in September 1941 to replace  275 Battery ; served in Normandy from June 1944 and later at Antwerp
and:  Honourable Artillery Company Infantry Battalion became:  162nd (Honourable Artillery Company) Officer Cadet Training Unit in September
1939; most men trained, commissioned and transferred to other units; core became:
 Reconnaissance Wing of Royal Armoured Corps, Officer Cadet Training Unit (Honourable Artillery Company Squadron) in October 1942 and:
 Honourable Artillery Company Companies in 13th (Home Defence) Battalion, The Royal Fusiliers re-designated as:  A Company and  B Company 
 
 
 WW2 
Battle Honours awarded to Honourable Artillery Company:
 Bourguebus Ridge, Antwerp, Le Havre,   Rhine, North West Europe 1944-45, Knightsbridge, El Alamein, El Hamma,   Sbiba,    Thala, Tunis,    North Africa 1941-43,    Sicily 1943, Cassino II, Coriano,   Senio, Italy 1944-45 
 
1947
Honourable Artillery Company reorganised as:
 235th Royal Horse Artillery Regiment (Honourable Artillery Company) 
[formed from: 11th Royal Horse Artillery Regiment (Honourable Artillery Company)]
Re-designated as:
 1st Regiment Honourable Artillery Company (Royal Horse Artillery)  with  A, B  and  C 
 Battery 
and:
 238th Royal Horse Artillery Regiment (Honourable Artillery Company) 
[formed from: Regional Headquarters, 273, 274 and 383 Battery of 86th Heavy
Anti-Aircraft Regiment (Honourable Artillery Company)]
Re-designated as:
 2nd Regiment Honourable Artillery Company (Heavy Anti-Aircraft)  with 
 D, E  and
 F Battery) and: 
 G Locating Battery, Honourable Artillery Company  formed by 1949 and: 
 Honourable Artillery Company Infantry Battalion formed with 
 1, 2, 3 and 
 4 Company Support Company and 
 Headquarters Company  soon added and:
 Honourable Artillery Company Cadet Battalion  formed
 
 
 1955 
 2nd Regiment Honourable Artillery Company (Heavy Anti-Aircraft)  disbanded
 
 1958 
 Honourable Artillery Company Cadet Battalion disbanded
 
 1961 
Honourable Artillery Company reorganised as:
 
 Regimental Headquarters  with  Officer Training Wing 
 
 1st Regiment Honourable Artillery Company (Royal Horse Artillery)  with  A, B  and
 
 C Battery  and  G Locating Battery 
 
 Honourable Artillery Company Infantry Battalion  with  1, 2, 3 and  4 Company 
 
 1964 
1st Regiment Honourable Artillery Company (Royal Horse Artillery)
 
 1st Field Regiment, Honourable Artillery Company (Royal Horse Artillery) 
 
 1967 
Honourable Artillery Company re-designated as:
 
 Honourable Artillery Company (Territorial and Army Volunteer Reserve) 
 
Territorial and Army Volunteer Reserve II (NATO units):
 
 Grenadier Company, Yager Company 
 
Territorial and Army Volunteer Reserve III (Home Defence units) formed from:
 
 Light Company and  C Battery 
 
Territorial and Army Volunteer Reserve IV:
 
 1969 
Territorial and Army Volunteer Reserve III establishment disbanded and  Light Company  and
 
 C Battery integrated into Territorial and Army Volunteer Reserve II
 
 1971 
Honourable Artillery Company (Territorial and Army Volunteer Reserve) reorganised as:
 
Territorial and Army Volunteer Reserve II (NATO units):
 
 Grenadier Company, Yager Company, Light Company 
 
 A Battery, B Battery, C Battery 
 
 1973 
Reorganised as:
 Regimental Headquarters  with
1 and  2 Squadron for operational role
 3 and  4 Squadron  to provide home defence, with 3 Squadron as gun support unit and
4 Squadron as training wing
 Band and  Corps of Drums 
 
 
1974 
Gun Troop added; formed under No. 4 Squadron 
 
1979 
Light Cavalry  troop formed for ceremonial duties (received a Royal Warrant in 2004)
 
 1985 
Honourable Artillery Company re-designated as:
 Honourable Artillery Company (Territorial Army )
Reorganised as:
1, 2  and  3 Squadron 
Headquarters Squadron (added in 1983)
Gun Troop 
A Company  and  B Company Home Service Force formed; re-designated in 1987 as:
1 and  2 Company Home Service Force; combined and re-designated in 1992 as:
 Infantry Company Home Service Force and disbanded in 1994
 
 1993-2008 
Honourable Artillery Company reorganised as:
1, 2 and  3 Squadron, providing Surveillance and Target Acquisition patrols
Signal Squadron (formed in 1994 from one troop each of 1, 2 and 3 Squadron)
Headquarters Squadron 
Gun Troop (disbanded 2004)
 Liaison Officer Troop (the re-roled Gun Troop from 2005)
Band  and  Corps of Drums