Auxiliaries are personnel that assist the military or police but are organised differently from such forces. Auxiliary may be volunteers undertaking support functions or performing certain duties such as garrison troops, usually on a part-time basis. Unlike a military reserve force, an auxiliary force does not have the same degree of training as regular soldiers or integration into a fighting force. Some are former military active duty personnel and actually have more training than their counterparts.
Historically the designation auxiliary has also been given to foreign or allied troops in the service of a nation at war. In the context of colonial troops, locally recruited irregulars were often described as auxiliaries.
Auxiliaries in the Roman army were recruited from provincial tribal groups who did not have Roman citizenship. As the Roman army of the Republican and early Empire periods was essentially based on the heavy infantry who made up the legions, it favored the recruitment of auxiliaries that excelled in supplementary roles. These included specialists such as missile troops (e.g. Balearic slingers and Cretan archers), cavalry (recruited among peoples such as the Numidians, and the Thracians), or light infantry. Auxiliaries were not paid at the same rate as legionaries, but could earn Roman citizenship after a fixed term of service.
By the 2nd Century AD the auxiliaries had been organised into permanent units, broadly grouped as Ala (cavalry), Cohors (infantry) and Cohors equitata (infantry with a cavalry element). Both cavalry alae and infantry cohors numbered between 480 and 600 men each. The mixed cohors equitata usually consisted of 6 centuries of foot soldiers and six squadrons of horsemen. Specialist units of slingers, scouts, archers and camel mounted detachments continued in existence as separate units with a regional recruitment basis.
United Kingdom and British Empire
During the Second Boer War Boer auxiliaries were employed by the British Army under the designation of "National Scouts". Recruited in significant numbers towards the end of the war from Afrikaner prisoners and defectors, they were known as hensoppers ("hands-uppers" i.e. collaborators) by their fellow Boers.
Prior to the creation of the Territorial Force in 1908, the term "Auxiliary Forces" was used by the British Army to collectively cover Yeomanry, Militia and Volunteers. That is to say the various part-time units maintained to act in support of the Regular Army (UK).
The Auxiliary Division was a British paramilitary police unit raised during the Irish War of Independence 1919–21. Recruited from former officers of the British Army who had served during World War I, the Auxiliary Division was a motorized mobile force nominally forming part of the Royal Irish Constabulary.
In 1941 the British Government created an organization of Auxiliary Units in southern England who would wage a guerilla war against occupying forces should Britain be invaded by the Nazis. Since the invasion never came, they were ultimately never used in combat. The Auxiliary Units were meant to carry out assaults on German units, along with damaging train lines and aircraft if necessary.
Whilst working as full-time, active duty personnel, the women's services of WWII were titled as or seen as auxiliaries to the male services. These services were:
- Women's Royal Naval Service
- Auxiliary Territorial Service
- Women's Auxiliary Air Force
- Air Transport Auxiliary
- Women's Home Defence
- Women's Auxiliary Service (Burma)
The Royal Auxiliary Air Force was originally an auxiliary of the Royal Air Force, when it was first conceived and formed in 1924. Today the RAuxAF acts as a military reserve; this is reflected in its more common name 'RAF Reserve'.
Other former British military or governmental auxiliary organizations included:
- Royal Maritime Auxiliary Service a former auxiliary to the Royal Navy
- Royal Naval Auxiliary Service a former auxiliary to the Royal Navy
- Royal Naval Minewatching Service a former auxiliary to the Royal Navy
- Royal Naval Supply and Transport Service a former auxiliary to the Royal Navy
- Royal Observer Corps a former auxiliary to the Royal Air Force
Auxiliary organizations of other countries of the British Empire:
- New Zealand
France made extensive use of tribal allies (goumiers) as auxiliaries in its North African possessions. During the Algerian War of 1954-62 large numbers of Muslim auxiliaries (Harkis) were employed in support of regular French forces.
German paramilitary police forces, called Hilfspolizei or Schutzmannschaft, were raised during World War II and were the collaborationist auxiliary police battalions of locally recruited police, which were created to fight the resistance during World War II mostly in occupied Eastern European countries. Hilfspolizei refers also to German auxiliary police units. There was also a HIPO Corps in occupied Denmark. The term had also been applied to some units created in 1933 by the early Nazi government (mostly from members of SA and SS) and disbanded the same year due to international protests.
With an increase in the amount of men needed to serve on the front lines, women were allowed to serve as auxiliaries to the Wehrmacht, known as Wehrmachthelferin, to take over duties within Germany freeing up men. From 12 February 1945, the Nazis conscripted German women and girls into the auxiliaries of the Volkssturm. Correspondingly, girls as young as 14 years were trained in the use of small arms, panzerfausts, machine guns, and hand grenades from December 1944 through May 1945.
Hiwis were auxiliary forces recruited from the indigenous populations in the areas of Eastern Europe first annexed by the Soviet Union and then occupied by Nazi Germany. Adolf Hitler reluctantly agreed to allow recruitment of Soviet citizens in the Rear Areas during Operation Barbarossa. In a short period of time, many of them were moved to combat units.
- Women's Radio Corps
- Women Airforce Service Pilots
- Ground Observer Corps
- Women's Flying Training Detachment
- United States Coast Guard (USCG) Women's Reserve
- United States Marine Corps Women's Reserve
- United States Naval Reserve (Women's Reserve)
- Women's Army Volunteer Corps
- Women's Army Auxiliary Corps
Current military or governmental auxiliaries
- Australian Red Cross, an auxiliary to government for humanitarian aid and emergency management
- Auxiliary Police
- Canadian Coast Guard Auxiliary, an auxiliary to the Canadian Coast Guard
- Canadian Forces Affiliate Radio System, an auxiliary to the Canadian Armed Forces
- Canadian Rangers, an auxiliary to the Canadian Army
- Auxiliary Police
- Auxiliary Medical Service, an auxiliary to the Fire Services Department, Hong Kong
- Hong Kong Auxiliary Police Force, an auxiliary to the Hong Kong Police Force
- Auxiliary Forces, a paramilitary force.
- Auxiliary Police and Volunteer Special Constabulary, auxiliaries of the Singapore Police Force
- SAF Volunteer Corps, an auxiliary of the Singapore Armed Forces
- Civil Defence Auxiliary Unit, an auxiliary of the Singapore Civil Defence Force
- Air Force Volunteers Association (Flygvapenfrivilligas riksförbund, FVRF), an auxiliary of the Swedish Air Force
- Swedish Voluntary Flying Corps (Frivilliga flygkåren, FFK), an auxiliary of the Home Guard
- Swedish Voluntary Radio Organization (Frivilliga radioorganisationen), an auxiliary of the Home Guard
- Swedish Women's Voluntary Defence Organization (Riksförbundet Sveriges lottakårer), an auxiliary of the Home Guard
- Swedish Parachute Association (Svenska fallskärmsförbundet), an auxiliary of the Home Guard
- Swedish Auxiliary Naval Corps (Sjövärnskåren), an auxiliary of the Swedish Navy and Home Guard
- Royal Fleet Auxiliary of the British Royal Navy
- First Aid Nursing Yeomanry auxiliary providing medical response support to Civil and Military authorities within London during a major event or incident.
- Special Constabulary, auxiliary police to various Police Services in the UK.
- Civil Air Patrol, an auxiliary of the United States Air Force.
- Marine Corps Cyber Auxiliary, an auxiliary of the United States Marine Corps.
- Military Auxiliary Radio System, a civilian auxiliary of the United States Armed Services.
- United States Coast Guard Auxiliary, the uniformed auxiliary of the United States Coast Guard.
- United States Merchant Marine, an auxiliary of the United States Navy
- Connecticut Auxiliary State Police provides auxiliary police services within the state of Connecticut.
- Florida Highway Patrol Auxiliary provides auxiliary police services within the state of Florida.
- Illinois Police Reserves provides auxiliary police services within the state of Illinois.
- Indiana Law Enforcement Academy provides training for members to serve as auxiliary police officer throughout the state of Indiana.
- Ohio State Highway Patrol Auxiliary provides auxiliary police services within the state of Ohio.
- New Hampshire State Police Auxiliary Troopers provide auxiliary police services within the state of New Hampshire.
- New Mexico Mounted Patrol provide auxiliary police services within the state of New Mexico.
- Penn State University Student Auxiliary Officers provide auxiliary police services to Penn State University.
- Vermont State Police Auxiliary provides auxiliary police services within the state of Vermont.
- Arlington County Police Department Auxiliary provides auxiliary police services for Arlington County, Virginia.
- Cheltenham Township Auxiliary Police provide auxiliary police services for Cheltenham Township, Pennsylvania
- Fair Lawn Auxiliary Police provides auxiliary police services for Fair Lawn, New Jersey.
- Greenburgh Auxiliary Police provides auxiliary police services for Greenburgh, New York.
- Hazlet Township Auxiliary Police provides auxiliary police services for Hazlet, New Jersey.
- Los Angeles County Sheriff's Department Reserves provide auxiliary police services for Los Angeles, California.
- Madison Auxiliary Police Unit provides auxiliary police services for Madison, New Jersey.
- Metuchen Auxiliary Police Department provides auxiliary police services for Metuchen, New Jersey.
- Nassau County Police Department Auxiliary provides auxiliary police services for Nassau County, New York.
- New York City Police Department Auxiliary Police provides auxiliary police services for New York City.
- Old Bridge Township Auxiliary Police provides auxiliary police services for Old Bridge Township, New Jersey.
- Rockland County Sheriff's Office Reserve Force provides auxiliary police services for Rockland County, New York.
- Sayreville Police Auxiliary provides auxiliary police services for Sayreville, New Jersey.
- Waltham Auxiliary Police provides auxiliary police services for Waltham, Massachusetts.
- Concise Oxford Dictionary, ISBN 0-19-861131-5
- Simkins, Michael. The Roman Army from Caesar to Trajan. p. 7. ISBN 0-85045-191-4.
- Wary, Raffaele D'Amato. Roman Army Units in the Eastern Provinces (1). p. 13. ISBN 978-1-4728-2176-8.
- Pakenham, Thomas. The Boer War. pp. 542 & 571. ISBN 0-7474-0976-5.
- Encyclopaedia Britannica, Eleventh Edition, Volume 3, p. 50
- Larcade, Jean-Louis. Zouaves & Tirailleurs: Vol 1. p. 280. ISBN 2-9515171-0-6.
- Windrow, Martin. The Algerian War 1854-62. p. 20. ISBN 1-85532-658-2.
- Ivanov & Jowett (2004). The Russo-Japanese War 1904–05. Osprey Publishing Ltd. pp. 12, 13, 46.
- "Archived copy". Archived from the original on 26 October 2007. Retrieved 7 November 2012.CS1 maint: archived copy as title (link)
- Richard Wires (1985). Terminology the Third Reich. Ball State University.
- Christopher Ailsby (1998). SS: Hell on the Eastern Front: The Waffen-SS War in Russia, 1941–1945. MBI Pub., Company. pp. 9–. ISBN 978-0-7603-0538-6.
- Hildebrand (1984). The Third Reich, p. 82.
- Kater (2004). Hitler Youth, p. 238.
- Thomas, Nigel (2015). "Eastern Troops. Hilfswillige". Hitler's Russian & Cossack Allies 1941–45. Bloomsbury Publishing. pp. 13–15, 57. ISBN 978-1472806895.
-  Australian Red Cross Submission to the Australian Defence White Paper 2015
- "About the Civil Air Patrol". Archived from the original on 21 December 2016. Retrieved 31 December 2016.
- About the Military Auxiliary Radio System
- About the Coast Guard Auxiliary
- About the Merchant Marines
- Volunteer Military Organizations: An Overlooked Asset
- About the Connecticut Auxiliary State Police
- About the Florida Highway Patrol Auxiliary
- About the Illinois Police Reserves
- About the Indiana Law Enforcement Academy
- "About the Ohio State Highway Patrol Auxiliary". Archived from the original on 1 January 2017. Retrieved 31 December 2016.
- About the New Hampshire State Police Auxiliary
- About the New Mexico Mounted Patrol
- About Penn State University Auxiliary Student Police
- About the Vermont State Police Auxiliary
- About the Arlington County Police Department Auxiliary
- "About the Cheltenham Township Auxiliary Police". Archived from the original on 1 January 2017. Retrieved 31 December 2016.
- "About Fair Lawn Auxiliary Police". Archived from the original on 7 December 2006. Retrieved 31 December 2016.
- About the Greenburgh Auxiliary Police
- About Hazlet Township Auxiliary Police
- About the Los Angeles County Sheriff's Department Reserves
- About Madison Police Auxiliary Unit
- About Metuchen Police Auxiliary
- About the Nassau County Police Auxiliary
- About the New York City Police Department Auxiliary
- About Old Bridge Township Auxiliary Police
- About the Rockland County Sheriff's Office Reserve Force
- About Sayreville Police Auxiliary
- About Waltham Auxiliary Police