Corps (/kɔːr/; pluralcorps/kɔːrz/; from Frenchcorps, from theLatincorpus "body") is a term used for several different kinds of organization. A military innovation byNapoleon I, the formation was formally introduced March 1, 1800, when Napoleon ordered GeneralJean Victor Marie Moreau to divide his command into four corps.[1] Before it came into force in 1800, the idea of corps was already in its infancy (for example, Jourdan'sArmy of Sambre and Meuse in 1795 was divided into 3 corps), but it could not take a definite form due to the relatively small size of the individual armies. Only Moreau granted the corps legal status in 1800; Napoleon finally developed them in 1805.[2] The size of a corps varies greatly, but two to five divisions and anywhere from 40,000 to 80,000 are the numbers stated by the US Department of Defense.
anoperational formation, sometimes known as afield corps, which consists of two or moredivisions, such as theCorps d'armée, later known asI Corps ("First Corps") of Napoleon I'sGrande Armée);
In many armies, a corps is a battlefield formation composed of two or moredivisions, and typically commanded by alieutenant general. DuringWorld War I andWorld War II, due to the large scale of combat, multiple corps were combined intoarmies which then formed intoarmy groups. In Western armies with numbered corps, the number is often indicated inRoman numerals (e.g.,VII Corps).
Canada first fielded a corps-sized formation in the First World War; theCanadian Corps was unique in that its composition did not change from inception to the war's end, in contrast to British corps in France and Flanders. The Canadian Corps consisted of four Canadian divisions. After the Armistice, the peacetimeCanadian militia was nominally organized into corps and divisions but no full-time formations larger than a battalion were ever trained or exercised. Early in the Second World War, Canada's contribution to the British-French forces fighting the Germans was limited to a single division. After the fall of France in June 1940, a second division moved to England, coming under command of a Canadian corps headquarters. This corps was renamedI Canadian Corps as a second corps headquarters was established in the UK, with the eventual formation of five Canadian divisions in England. I Canadian Corps eventually fought in Italy,II Canadian Corps in northwest Europe, and the two were reunited in early 1945. After the formations were disbanded after VE Day, Canada has never subsequently organized a corps headquarters.
Royal Canadian Army Cadets: A corps size in the RCAC is different everywhere, depending on the size. The commanding officer can be acaptain (Previously, Commanding Officers of a large corps could have been a Major, but that capability has been removed with the creation of CJCR Group Order 5511-1)
TheNational Revolutionary Army (NRA) corps (軍團) was a type of military organization used by theChinese Republic, and usually exercised command over two to threeNRA divisions and often a number of independentbrigades orregiments and supporting units. The Chinese Republic had 133 corps during theSecond Sino-Japanese War. After losses in the early part of the war, under the 1938 reforms, the remaining scarce artillery and the other support formations were withdrawn from the division and was held at corps, or army level or higher. The corps became the basic tactical unit of the NRA having strength nearly equivalent to an allieddivision.
The modernPeople's Liberation Army Ground Forcegroup army (集团军) is the closest equivalent of a corps. After the military reforms of the early 2010s, a typical PLA group army consists of six combined arms brigades, plus additional artillery, air defence, engineering, sustainment, special operations and army aviation assets. Each formation contains approximately 30,000 combat troops and several thousands more supporting personnel.
TheFrench Imperial Army underNapoleon I used corps-sized formations (French:corps d'armée) as the first formal combined-arms groupings ofdivisions with reasonably stable manning and equipment establishments. Napoleon I first used thecorps d'armée in 1805. The use of thecorps d'armée was a military innovation that provided Napoleon I with a significant battlefield advantage in the early phases of theNapoleonic Wars. The corps was designed to be an independent military group containing cavalry, artillery and infantry, and capable of defending against a numerically superior foe. This allowed Napoleon I to mass the bulk of his forces to effect a penetration into a weak section of enemy lines without risking his own communications or flank. This innovation stimulated other European powers to adopt similar military structures. The corps has remained an echelon of French Army organization to the modern day.
As fixed military formation already in peace-time it was used almost in all European armies afterBattle of Ulm in 1805. In Prussia it was introduced byOrder of His Majesty (German:Allerhöchste Kabinetts-Order) from 5 November 1816, in order to strengthen the readiness to war.
TheIndian Army has14 corps, each commanded by ageneral officer commanding (GOC), known as the corps commander, who holds the rank oflieutenant general. Each corps is composed of three or four divisions. There are three types of corps in the Indian Army: strike, holding and mixed. The corps HQ is the highest field formation in the army.
ThePakistan Army has nine manoeuvre corps, each commanded by alieutenant general. Each corps is composed of at least two divisions. The corps HQ is the highest field formation in the army.
ThePolish Armed Forces usedindependent operational groups in the place of the corps before and duringWorld War II. An example would beIndependent Operational Group Polesie. The groups, as the name indicates, were more flexible and showed greater capacity to absorb and integrate elements of broken units over a period of just a couple days and keep cohesion during theSeptember Campaign than more traditional army units such as divisions, regiments, or even brigades.
In Russia (then theEmpire), corps were officially introduced in 1810, under EmperorAlexander I, when 5 corps of different compositions were formed from allbranches of the military.[6]
Wellington formed acorps d'armée in 1815 for commanding his mixed allied force of four divisions against Napoleon I.
When the British Army was expanded from an expeditionary force in the First World War, corps were created to manage the large numbers of divisions. TheBritish corps in World War I included 23 infantry corps and a few mounted corps. The word was adopted for other special formations such as theOfficers Training Corps. Military training of teenage boys is undertaken at secondary schools through theCombined Cadet Force, in which participation was compulsory at some schools in the 1950s. Schoolboy jargon called the CCF simply "Corps".
TheBritish Army still has a corps headquarters for operational control of forces.I Corps of theBritish Army of the Rhine was redesignated theAllied Rapid Reaction Corps in 1994. It is no longer a purely British formation, although the UK is the "framework nation" and provides most of the staff for the headquarters. A purely national Corps headquarters could be quickly reconstituted if necessary.
It took command of the International Security Assistance Force in Afghanistan on 4 May 2006. Previously, it was deployed as the headquarters commanding land forces during theKosovo War in 1999 and also saw service inBosnia and Herzegovina, commanding the initial stages of theIFOR deployment prior to that in 1996. Otherwise, the only time a British corps headquarters has been operationally deployed since 1945 wasII Corps during theSuez Crisis.
The structure of a field corps in theUnited States Army is not permanent. On the battlefield, the corps is the highest level of the forces that is concerned with actual combat and operational deployment. Higher levels of command are concerned with administration rather than operations, at least under current doctrine. The corps provides operational direction for the forces under its command.
As of 2014, the active field corps in the US Army areI Corps,III Corps, andXVIII Airborne Corps; their lineages derive from three of the corps formed during World War I (I and III Corps) and World War II (XVIII Airborne Corps). On 12 February 2020, it was announced that the Army was reactivatingV Corps to bolster the presence of US forces in Europe.
The first field corps in theUnited States Army were legalized during theAmerican Civil War by an act of Congress on 17 July 1862, although the term had been used previously to refer to any large portion of the army.[7] Major GeneralGeorge B. McClellan, for example, planned to organize theArmy of the Potomac into corps of two or moredivisions and about 25,000 soldiers. However, he delayed doing so, partly for lack of experienced officers, and partly for political reasons, until March 1862 whenPresident Lincoln ordered their creation.[8]
The exact composition of a corps in theUnion Army varied during the war, though it usually consisted of two to six divisions (three on average) for approximately 36,000 soldiers.[7][9] AfterAmbrose Burnside was given command of the Army of the Potomac in November 1862, he reorganized it into three "grand divisions" of two corps and a cavalry division each, but this structure was abolished whenJoseph Hooker took over February 1863. This also led to the creation of a dedicatedCavalry Corps of three divisions andhorse artillery assigned to the corps headquarters. In the early years of the war,field artillery was either part of an artillery reserve under direct army control or assigned to individual divisions. However, after theBattle of Chancellorsville the divisional artillery was placed under corps control, with each corps assigned abrigade of four to sixbatteries commanded by the senior-most artillery officer. In general, the other field armies tended to model their organization after the Army of the Potomac, including the gradual development of corps.[8][10]
Corps were commanded by major generals because Congress refused to promote officers past that grade (with the exception ofUlysses S. Grant tolieutenant general in 1864).[10] To assist with their command, generals were allowed a number ofaides-de-camp and ageneral staff of other officers. This staff consisted of a chief of cavalry, a chief of artillery, and representatives of theWar Department's various bureaus:[11] an assistantadjutant general, aquartermaster, an assistantinspector general, a commissary of subsistence, an ordnance officer (all with the rank oflieutenant colonel), and a medical director. However, there were no dedicatedcombat service support formations as part of the corps. This meant that either civilian workers had to be hired or line soldiers detailed from their units to carry out the necessary tasks.[12]
Initially, corps were numbered in relation to their field army, such as I Army Corps, Army of the Potomac. After a while these numerical designations became unique to each corps regardless of the army to which they were assigned.[8][10] Although designated with numbers that are sometimes the same as those found in the modern US Army, there is no direct lineage between the 43 Union field corps of the Civil War and those with similar names in the modern era, due to congressional legislation caused by the outcry from veterans of theGrand Army of the Republic during theSpanish–American War.[citation needed]
In theConfederate States Army, field corps were authorized in November 1862. They were commanded by lieutenant generals, and were usually larger than theirUnion Army counterparts because their divisions contained more brigades, each of which could contain more regiments. All of the Confederate corps at theBattle of Gettysburg, for instance, exceeded 20,000 men. However, for both armies, unit sizes varied dramatically with attrition throughout the war. In Civil War usages, by both sides, it was common to write out the number, thus "Twenty-first Army Corps", a practice that is usually ignored in modern histories of the war.
Although the US Army in the years following the Civil War lacked standing organization at the corps and division levels, it moved swiftly to adopt these during the mobilization for the Spanish–American War in the spring of 1898. On 7 May, General Order 36 called for the establishment of seven "army corps" (repeating the nomenclature of the Civil War); an eighth was authorized later that month.[13] Two of these saw action as a unit: the Fifth in Cuba and the Eighth in the Philippines; elements of theFirst,Fourth, andSeventh made up the invasion force for Puerto Rico (the Second,Third, and Seventh provided replacements and occupation troops in Cuba, while theSixth was never organized). The corps headquarters were disbanded during the months following the signing of the peace treaty (with the exception of the Eighth Army Corps, which remained active until 1900 due to the eruption of thePhilippine–American War), and like the corps of the Civil War, their lineage ends at that point.
During World War I, theAmerican Expeditionary Forces (AEF) adopted the common European usage of designating field corps byRoman numerals. Several "corps areas" were designated under the authority of theNational Defense Act of 1920, but played little role until the Army's buildup for World War II. While some of the lower numbered corps were used for various exercises, the inter-war years corps served mostly as a pool of units.[14] During that war, the Marine Corps organized corps headquarters for the first time, theI Marine (laterIII Amphibious Corps) andV Amphibious Corps. The Army ultimately designated 25 field corps (I–XVI, XVIII–XXIV, XXXVI, andI Armored Corps) during World War II.
After theKorean War, the Army and Marines diverged in their approach to the concept of the field corps. The Army continued to group its divisions into traditional corps organizations in the Continental United States (CONUS), West Germany (V Corps andVII Corps), and South Korea (I Corps). However, during theVietnam War, the Army designated its corps-level headquarters in South Vietnam asI Field Force andII Field Force to avoid confusion with theARVN corps areas.[15] As of July 2016, the Army deactivated all corps headquarters save three CONUS based corps (I Corps - Washington,III Corps - Texas, andXVIII Airborne Corps - North Carolina).
In the 1960s, the Marine Corps activated theI Marine Expeditionary Force (I MEF) on Okinawa (based in California since 1971) andII Marine Expeditionary Force (II MEF) in North Carolina, and re-activated the III Amphibious Corps (which had been deactivated in 1946) asIII Marine Expeditionary Force (III MEF) in South Vietnam (re-deployed to Okinawa in 1971). In 1965, all three MEFs were subsequently re-designated as Marine amphibious forces or MAFs, and in 1988 all three Marine Corps corps-level commands were again re-designated asMarine expeditionary forces (MEF). The MEF had evolved into a self-contained, corps-level,Marine air-ground task force (MAGTF) consisting of a MEF headquarters group, a Marine division, a Marine aircraft wing, and a force service support group (re-designated as Marine logistics group in 2005).
The pre–World War IIRed Army of the formerUSSR hadrifle corps much like in the Western sense with approximately three divisions to a corps.[16] However, after the war started, the recently purged Soviet senior command (Stavka) structure was apparently unable to handle the formations, and the armies and corps were integrated. Rifle corps were re-established during the war afterRed Army commanders had gained experience handling larger formations. Before and during World War II, however, Soviet armoured units were organized into corps. The pre-warmechanized corps were made up of divisions. In the reorganizations, these "corps" were reorganized into tankbrigades and support units, with no division structure. Owing to this, they are sometimes, informally, referred to as "brigade buckets".
After the war, the tank and mechanized corps were re-rated as divisions. During the reforms of 1956–58, most of the corps were again disbanded to create the new combined arms and tank armies. A few corps were nevertheless retained. The Vyborg and Archangel Corps of theLeningrad Military District were smaller armies with three low-readiness motorized rifle divisions each. In the 1980s "Unified Corps" on the brigade pattern were created in theBelorussian Military District (Western TVD/Strategic Direction) and the48th Separate Guards Army Corps in theTransbaikal Military District, but abandoned after a few years.
TheSoviet Air Forces used ground terminology for its formations down to squadron level. As intermediates between theaviation division and the air army were corps—these also had three air divisions each.
An Air Defence Corps ('KPVO') is an operational-tactical formation (in the past - the highest tactical formation) of the formerSoviet Air Defence Forces and nowRussian Air Defence Forces/Aerospace Forces. The purpose of the such a corps is to protect important administrative, industrial and economic centers and regions of the country, groupings of troops (forces) and military facilities within the established limits of responsibility against air strikes. In organizational terms, an air defence corps is part of the district (or a separate army) of the Air Defence Forces. Also some air defence corps were separate.
On the basis of individual corps,air defence zones orair defence corps areas could be created. The firstKPVO were created in February 1938 for the air defence ofMoscow,Leningrad andBaku (respectively 1st, 2nd and 3rd) based on anti-aircraft artillery divisions and air defence brigade (3rd KPVO). The staff of theKPVO included: 4-6 anti-aircraft artillery regiments, 1 anti-aircraft machine-gun regiment, 1 searchlight regiment (or battalion), 1-2 regiments (or divisions)barrage balloons, 1- 2 regiments (or battalions) of visual observation, warning and communications (VNOS), and a separate communications battalion. From September 1938 to November 1940, theKPVO also included 1-2 regiments (battalions) of local air defence.
During the Great Patriotic War from November 1941 to April 1944 the air defence corps were renamed into air defence corps areas (such as theStalingrad Corps Region). The corps districts included up to 9 anti-aircraft artillery regiments and 14 separate anti-aircraft artillery battalions, up to 3 anti-aircraft machine-gun regiments, 1 searchlight regiment, 1 regiment (or division) of barrage balloons, up to 4 regiments (or separate battalions) VNOS, and a communications regiment (or a separate battalion). In 1945, air defence corps could include 1 anti-aircraft artillery brigade or division.
Air defence fighters operating within the limits of responsibility of theKPVO was transferred to the corps. By the end of the war, there were 14KPVO in the Active Army, of which 5 corps continued to carry out the tasks assigned to them even after the war, and the rest of the corps were disbanded.
In July 1947, allKPVO were renamed anti-aircraft artillery corps. In January 1949, part of these corps was reorganized intoair defence areas. From December 1948 to January 1949, all anti-aircraft artillery corps were disbanded.
In June 1954, for the defense of the main industrial and economic centers and regions of the USSR, 10 air defence corps were re-created. At the same time, in addition to anti-aircraft artillery formations, fighter aviation regiments and divisions were included in the corps. Since the late 1950s, anti-aircraft artillery units have been replaced by anti-aircraft missile formations and formations of radio engineering troops. Searchlight and barrage balloon units were also abolished.
In theWarsaw Pact countries, groupings similar to the Soviet air defence corps were also created. In June–July 1960, allKPVO were enlarged and consisted of: anti-aircraft missile regiments and brigades, air defense fighter regiments, radio engineering regiments and brigades, separateelectronic warfare battalions, regiments and battalions of communications and logistics institutions.[17][18]
In many English-speaking countries and other countries influenced by British military traditions, a corps is also a grouping of personnel by common function, also known as anarm,service,mustering orbranch.
In the British Army, an administrative corps performs much the same role – for personnel that otherwise lack them – as aceremonial regiment. An administrative corps therefore has its owncap badge,stable belt, and other insignia and traditions.
In some cases, the term corps is also used informally, for looser groupings of independent regiments and other units – and without many or any unifyingregalia,military traditions or other accoutrements – such as theRoyal Armoured Corps or the "Corps of Infantry".
In Australia, soldiers belong foremost to a corps which defines a common function or employment across the army. TheAustralian Army has a system of coloured lanyards, which each identify a soldier as part of a specific corps (or sometimes individual battalion). This lanyard is a woven piece of cord which is worn on ceremonial uniforms and dates back to the issue of clasp knives in the early 20th century which were secured to the uniform by a length of cord.
If a soldier is posted to a unit outside of their parent corps, except in some circumstances the soldier continues to wear the hat badge and lanyard of their corps (e.g. a clerk posted to an infantry battalion would wear the hat badge of the Royal Australian Army Ordnance Corps but would wear the lanyard of the battalion they are posted to).
In New Zealand, soldiers belong foremost to a corps which defines a common function or employment across the army.
A corps in theNew Zealand Army is an administrative group that comprises members of similar work functions.[22]
If a soldier is posted to a unit outside of their parent corps, except in some circumstances the soldier continues to wear the hat badge of their corps (e.g. asupply technician posted to an infantry battalion would wear the hat badge of theRoyal New Zealand Army Logistic Regiment.
3)US Navy officers who are notline officers (i.e., those who exercise general command authority and are eligible for operational command positions, as opposed to officers who normally exercise authority only within their own specialty[24]) are commissioned into variousStaff Corps. These officers are specialists in career fields that are professions unto themselves, such as ministers, civil engineers, architects, dentists, lawyers, physicians, healthcare administrators, healthcare scientists, clinical care providers, nurses, financial managers, and logistics and supply specialists. Thesecorps include theChaplain Corps,Civil Engineer Corps,Dental Corps*,Judge Advocate General's Corps,Medical Corps*,Medical Service Corps*,Nurse Corps*, and theSupply Corps. The Navy also has aHospital Corps consisting of enlisted medical technicians. The Hospital Corps, along with the four Navy health services corps listed above (indicated by asterisk), is one of the five corps of the NavyBureau of Medicine and Surgery.
The ambassadors, consuls and other foreign embassy staff in a country are collectively referred to as thediplomatic corps (French:corps diplomatique). InAustralia, embassy vehicles havelicence plates beginning with the letters DC (or DX).
The Salvation Army calls its local units/church "corps" (e.g. The Rockford Temple Corps, The St. Petersburg Citadel Corps), echoing the pseudomilitary name and structure of the organization.
Many volunteer municipal or university ambulance, rescue, and first-aid squads are known as VACs (volunteerambulance corps). Prominent examples are theOrder of Malta (the largest in Ireland),Hatzolah (largest VAC network worldwide),Hackensack VAC. The usage of the termambulance corps dates toAmerican Civil War Major GeneralGeorge B. McClellan's General Order No 147 to create an "ambulance corps" within theUnion Army.[27] GO 147 usedcorps in one of its standard military senses. However, subsequent formations of non-military ambulance squads continued to use the term, even where they adhere less to paramilitary organizational structure.
ThePeace Corps was organized by the United States as an "army" of volunteers.
^Odgers, George (1994).Diggers: The Australian Army, Navy and Air Force in Eleven Wars. Vol. 1. Sydney, New South Wales: Lansdowne. p. 86.ISBN978-1863023870.
^Grey, Jeffrey (2008).A Military History of Australia (3rd ed.). Melbourne, Victoria: Cambridge University Press. p. 107.ISBN978-0-521-69791-0.
^Novitsky, Vasily F.; Schwartz, Aleksey V. von; Apushkin, Vladimir A.; Schoultz, Gustav K. von (1911)."Армейскiй корпусъ" [Army corps].Военная энциклопедия Сытина (in Russian). Vol. 3: Аральская флотилия – Афонское сражение. Moscow: Типография Т-ва И. Д. Сытина. pp. 37–41. Retrieved16 September 2023.
^abEicher, J., Eicher, D. (2002). Civil War High Commands. United States: Stanford University Press. pages 65-66
^abcWilson, J. B. (1998). Maneuver and Firepower: The Evolution of Divisions and Separate Brigades. United States: Center of Military History, U.S. Army. pages 12-15
^abcMcGrath, John J. The Brigade: A History, Its Organization and Employment in the US Army. (2004). Fort Leavenworth, Kansas : Combat Studies Institute, US Army Command and General Staff College. pages 17-19
^Shrader, C. R., Newell, C. R. (2011). Of Duty Well and Faithfully Done: A History of the Regular Army in the Civil War. United States: Nebraska. page 71
^Kreidberg, Marvin; Henry, Morton (November 1955).History of Military Mobilization(PDF). Washington, DC: Department of the Army. pp. 144–145. Archived fromthe original(PDF) on 8 August 2014. Retrieved30 July 2014.
^Сергеев, Игорь Дмитриевич [Sergeev I.D.], ed. (1999).Military Encyclopedia, Volume 4, article "Corps". Moscow.:Voenizdat. pp. 204–209.ISBN5-203-01655-0.
^Nikolai Ogarkov, ed. (1977).Советская военная энциклопедия в 8-ми томах (2-е издание), Том 4, статьи Корпус, Корпус ПВО [Soviet Military Encyclopedia in 8 volumes (2nd Edition), Volume 4, articles "Corps" and "Air Defence Corps."]. Moscow:Voenizdat. pp. 372–373.
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