Regiment A regiment is a title used by some military unit s . The size of a regiment varies markedly , depending on the country and the arm of service . Historically , in the 17th and 18th centuries , a full - strength regiment was typically supposed to be a thousand men , and was commanded by a colonel . Today , there is no set size for a unit calling itself a " regiment " , which may be : Historical origin . The French term " régiment " entered military usage in Europe at the end of the 16th century , when armies evolved from collections of retinue s who followed knight s , to formally organised , permanent military forces . At that time , regiments usually were named after their commanding colonels , and disbanded at the end of the campaign or war ; the colonel and his regiment might recruit from and serve several monarchs or countries . Later , it was customary to name the regiment by its precedence in the line of battle , and to recruit from specific places , called cantons . The oldest regiments which still exist include the 1521 Swedish Life Guards , the 1537 British Honourable Artillery Company , the French " premier régiment d ' infanterie de ligne " , created from the ancient " bandes de Picardie " first established in 1479 , and the King ' s Own Immemorial Regiment of Spain , first established in 1248 during the conquest of Seville by King Ferdinand the Saint . In the 17th century brigades were formed as units combining infantry , cavalry , and artillery that were more effective than the older , single - arms regiments ; in many armies , brigades replaced regiments . By the beginning of the 18th century regiments in most European continental armies had evolved into permanent units with distinctive titles and uniforms , each under the command of a colonel . When at full strength an infantry regiment normally comprised two field battalions of about 800 men each . A cavalry regiment numbered 600 to 900 troopers , making up a single entity . On campaign these numbers were soon reduced by casualties and detachments and it was sometimes necessary to amalgamate regiments or to withdraw them to a depot while recruits were obtained and trained . Regimental system . In the regimental system , each regiment is responsible for recruiting , training , and administration ; each regiment is permanently maintained and therefore the regiment will develop its unique " esprit de corps " because of its unitary history , traditions , recruitment , and function . Usually , the regiment is responsible for recruiting and administrating all of a soldier ' s military career . Depending upon the country , regiments can be either combat units or administrative units or both . This is often contrasted to the " continental system " adopted by many other armies . In the continental system , the division is the functional army unit , and its commander is the administrator of every aspect of the formation : his staff train and administer the soldiers , officers , and commanders of the division ' s subordinate units . Generally , divisions are garrisoned together and share the same installations : thus , in divisional administration , a battalion commanding officer is just another officer in a chain of command . Soldiers and officers are transferred in and out of divisions as required . Some regiments recruited from specific geographical areas , and usually incorporated the place name into the regimental name . In other cases , regiments would recruit from a given age group within a nation ( e . g . Zulu Impis ) , an ethnic group ( e . g . the Gurkhas ) , or foreigners ( e . g . the French Foreign Legion ) . In other cases , new regiments were raised for new functions within an army ; e . g . the Fusiliers , the Parachute Regiment ( British Army ) , and the U . S . Army 75th Ranger Regiment . Disadvantages of the regimental system are hazardous regimental competition , a lack of interchangeability between units of different regiments , and more pronounced " old boy network s " within the military that may hamper efficiency and fairness . A key aspect of the regimental system is that the regiment or battalion is the fundamental tactical building block . This flows historically from the colonial period , when battalions were widely dispersed and virtually autonomous , but is easily adapted to a number of different purposes . For example , a regiment might include different types of battalions ( e . g . infantry or artillery ) of different origins ( e . g . regular or reserve ) . Within the regimental system , soldiers , and usually officers , are always posted to a tactical unit of their own regiment whenever posted to field duty . In addition to combat units , other organizations are very much part of the regimental family : regimental training schools , serving members on " extra - regimental employment " , regimental associations ( retirees ) , bands and associated cadet groups . The aspects that an administrative regiment might have in common include a symbolic colonel - in - chief ( often a member of the royal family ) , a colonel of the regiment or " honorary colonel " who protects the traditions and interests of the regimental family and insists on the maintenance of high standards , battle honours ( honours earned by one unit of an administrative regiment are credited to the regiment ) , ceremonial uniforms , cap badge s , peculiarities of insignia , stable belt s , and regimental marches and songs . The regiment usually has a traditional " home station " , which is often a historic garrison that houses the regimental museum and regimental headquarters . The latter has a modest staff to support regimental committees and administer both the regular members and the association ( s ) of retired members . Advantages and disadvantages . The regimental system is generally admired for the " esprit de corps " it engenders in its units ' members , but efforts to implement it in countries with a previously - existing continental system usually do not succeed . The system presents difficulties for military planners , who must deal with the problems of trying to keep soldiers of a regiment together throughout their careers and of administering separate garrisons , training and mess facilities . The regimental community of serving and retired members often makes it very difficult for planners to restructure forces by moving , merging or re - purposing units . In those armies where the continental system exists , the regimental system is criticised as parochial and as creating unnecessary rivalry between different regiments . The question is also raised as to whether it is healthy to develop soldiers more loyal to their regiment than to the military in general . In favour of the regimental system , it is worth noting that the United Kingdom has never suffered a military coup , or even seriously faced the prospect of one – this could in part be attributed to the " tribal " nature of the regimental system , which makes it more difficult for a charismatic leader to command the loyalty of the entire army . ( The English Civil War took place before the political creation of the United Kingdom . ) Commonwealth - style regiments have proven their worth throughout history in war and through lengthy and difficult policing missions . Regiments recruited from areas of political ferment ( such as Scotland , Wales , Ireland , Quebec , India , etc . ) , tend to perform particularly well because of the loyalty their members exhibit to the regiments . Generally , the regimental system is found to function best in countries with small - to medium - sized military forces where the problems of administering vast numbers of personnel are not as prevalent . The regimental system works particularly well in an environment in which the prime role of the army consists of small - scale police actions and counterinsurgency operations , requiring prolonged deployment away from home . In such a situation , co - ordination between regiments is rarely necessary , and the esprit de corps of the regiment provides an emotional substitute for the sense of public approval that an army receives at home . This is particularly relevant to British experience during the days of the empire , where the army was virtually continuously engaged in low - intensity conflict with insurgents , and full - scale warfare was the exception rather than the rule . A regimental system can also foster close links between the regiment and the community from which it is recruited . This sense of community ' ownership ' over local regiments can be seen in the public outcry over recent regimental amalgamations in the United Kingdom . On the other hand , recruitment from a single community can lead to a concentrated and potentially devastating local impact if the regiment takes heavy casualties . Further , the regimental system offers the advantage of grouping like units together for centralized administrative , training , and logistical purposes , thereby creating an “ economies of scale ” effect and its ensuing increased efficiency . An illustrative example of this is the modular integration employed by the United States Marine Corps , which can take elements from its regimentally grouped forces and specifically tailor combined arms task forces for a particular mission or the deployed Marine Expeditionary Unit s ( MEU ) . This is achievable partially because of the Marines mission adaptability , flexibility , philosophy , shared culture , history and overall esprit de corps , which allows for near seamless interoperability . Commonwealth armies . In the British Army and armies modelled on it ( such as the Australian , the New Zealand , the Canadian , the Indian and the Pakistani ) , the term " regiment " is used confusingly in two different ways : it can mean an administrative identity and grouping or a tactical unit . The modern British regimental system came about as a result of the 19th century Cardwell Reforms . In Commonwealth countries such as India , Pakistan , Australia , New Zealand and Canada the large administrative regiment has been the normal practice for many years . In the case of India " large regiments " of four to five battalions date from 1923 and since the 1950s many of these have expanded even further . As an example the Punjab Regiment has expanded from four battalions in 1956 to its present strength of 20 , while in Pakistan several regiments have over 50 battalions . In Canada , the regiment is a formation of one or more like units employed almost exclusively for reasons of heritage , the continuance of battle honor s and " espit de corps " . Most Canadian infantry regiments are reserve units composed entirely of one under - strength battalion of between 100 - 250 soldiers . The three regular force infantry regiments each consist of three regular force battalions of approximately 600 soldiers , in addition to one or more reserve battalions . Canadian battalions are employed tactically and administratively within mechanized brigade group s for regular units , or light brigade group s for reserve units . In Australia there is but one administrative infantry regiment in the regular army , the Royal Australian Regiment , consisting of all seven regular infantry battalions in the Army , including mechanised , motorised , light , commando and parachute infantry . The Australian Army Reserve also has state - based infantry regiments which administer the reserve infantry battalions . In Pakistan the word regiment is an administrative grouping . While different battalions may have different roles ( for example different battalions of the Frontier Force Regiment may be mechanized infantry , para infantry or mountain troops ) the regiment is considered to encompass all of them . British Army . In the British Army , for most purposes , the regiment is the largest " permanent " organisational unit . Above regimental level , organisation is changed to meet the tasks at hand . Because of their permanent nature , many regiments have long histories , often going back for centuries : the oldest British regiment still in existence is the Honourable Artillery Company , established in 1537 . The Royal Scots , formed in 1633 , was the oldest infantry regiment . It now forms part of the Royal Regiment of Scotland . In the United Kingdom , there existed until recently a number of administrative " divisions " in the infantry that encompassed several regiments , such as the Guards Division , the former Scottish Division ( now a single regiment ) , or the Light Division ( now also compressed into a multi - battalion single regiment ) . The reduction and consolidation of British infantry regiments that began in the late 1950s and concluded in 2006 has resulted in a system of administrative regiments each with several battalions , a band , a common badge and uniform etc . In the British regimental system the tactical regiment or battalion is the basic functional unit and its commanding officer more autonomous than in continental systems . Divisional and brigade commanders generally do not immerse themselves in the day - to - day functioning of a battalion – they can replace the commanding officer but will not micro - manage the unit . The regimental sergeant major is another key figure , responsible to the CO for unit discipline and the behaviour of the NCOs . It should however be noted that amalgamations beginning in the late 1950s and ending in 2006 have diluted the British regimental system through the now almost universal adoption of " large regiments " for the infantry of the Army . These units comprise up to six of the former battalions that previously had separate regimental status . Only the Guards regiments retain their historic separate identities . Armour . Armoured regiments in Canada since the end of the Second World War have usually consisted of a single tactical regiment . During the 1960s , three Canadian regiments had both regular and militia components , which were disbanded shortly after unification in 1968 . Currently , one regiment is organised with two tactical regiments , 12 Régiment blindé du Canada and 12 Régiment blindé du Canada ( Milice ) are both part of the administrative regiment 12 Régiment blindé du Canada . The only administrative armoured regiment of the British Army that consists of more than one tactical regiment is the Royal Tank Regiment , which currently has two ( 1 and 2 RTR ) , and once had many more . These two tactical regiments will soon be amalgamated into a single regiment . Artillery . All of a nation ' s artillery units are considered part of a single administrative regiment , but there are typically several tactical artillery regiments . They are designated by numbers , names or both . For example , the tactical regiments 1st Regiment , Royal Canadian Horse Artillery , 7th Toronto Regiment , RCA and many others are part of the single administrative regiment The Royal Regiment of Canadian Artillery . In Britain , the Royal Regiment of Artillery works in the same way . Infantry . Administrative infantry regiments are composed of one or more battalion s . When a regiment has only one battalion , the battalion may have exactly the same name as the regiment . For example , The North Saskatchewan Regiment is the only battalion in the administrative regiment of the same name . When there is more than one battalion , they are distinguished by numbers , subsidiary titles or both . In Britain , every infantry battalion bears a number , even if it is the only remaining battalion in the regiment ( in that case it is the 1st Battalion , with the exception of The Irish Regiment of Canada , which has a 2nd Battalion only ) . Until after the Second World War , every regiment had at least two battalions . Traditionally , the regular battalions were the 1st and 2nd Battalions , the militia ( later Special Reserve ) battalion was the 3rd Battalion , and the Territorial Army battalions were the 4th Battalion and up . A few regiments had up to four regular battalions and more than one militia battalion , which disrupted the numbering , but this was rare . For this reason , although the regular battalion today ( if there is only one ) will always be the 1st Battalion , the TA battalions may have non - consecutive numbers . In practice , it is impossible to exercise all the administrative functions of a true regiment when the regiment consists of a single unit . Soldiers , and particularly officers , cannot spend a full career in one battalion . Thus in the Armoured Corps , the traditional administrative " regiment " tends to play more of a ceremonial role , while in practice , its members are administered by their corps or " branch " as in the Artillery . Thus soldiers and officers can serve in many different " regiments " , changing hat badges without too much concern during their career . Indeed , in the artillery , all regiments wear the same badge . Corps . The British Army also has battalion - sized tactical regiments of the Royal Engineers , Royal Corps of Signals , Army Air Corps , Royal Logistic Corps and Royal Military Police . United States Army . The United States Army was also once organized into regiments , but in the 20th century the division became the tactical and administrative unit . Industrial management techniques were used to draft , assemble , equip , train and then employ huge masses of conscripted civilians in very short order , starting with minimal resources . Historically , a regiment consisted of three battalion s and the regiment headquarters ( HQ ) company . Training , administration and even tactical employment was centered at divisional level . Many , but not all combat support and logistics was also concentrated at that level . A new system , the Combat Arms Regimental System , or CARS , was adopted in 1957 to replace the old regimental system . CARS uses the Army ' s traditional regiments as parent organizations for historical purposes , but the primary building blocks are divisions , brigade s , and battalion s . Each battalion carries an association with a parent regiment , even though the regimental organization no longer exists . In some brigades several numbered battalions carrying the same regimental association may still serve together , and tend to consider themselves part of the traditional regiment when in fact they are independent battalions serving a brigade , rather than a regimental , headquarters . The CARS was replaced by the United States Army Regimental System ( USARS ) in 1981 . There are exceptions to USARS regimental titles , including the Armored Cavalry Regiment s and the 75th Ranger Regiment created in 1986 . On 1 October 2005 , the word " regiment " was formally appended to the name of all active and inactive CARS and USARS regiments . So , for example , the 1st Cavalry officially became titled the 1st Cavalry Regiment . United States Marine Corps . The USMC is divided into numbered regiments . Regardless of their purpose , Marine regiments are always referred to generically as " Marines " or " Marine Regiments " – never as " Marine Rifle Regiment " or " Marine Artillery Regiment . " For example , a Marine would consider himself to be a member of the 12th Marines or the 1st Marine Regiment . Marine regiments are commanded by Colonels and are usually composed of three to five battalions . The United States Marine Corps deploys battalions from its regiments in Marine Expeditionary Unit s or MEUs . However , a USMC regiment may deploy en masse as the ground combat element of a Marine Expeditionary Brigade or MEB . When attached to the MEB the Regiment is reinforced and redesignated a Regimental Combat Team ( RCT ) or a Regimental Landing Team ( RLT ) . Russian Army . The regiments ( ) of the Russian Army , and armed forces influenced by Russia consist of battalion s ( ) , in the infantry or tank troops , divisions ( ) in the artillery troops , and squadrons ( ) in aviation troops . Land forces regiments also include support units – companies ( ) and / or platoon s ( ) . Soviet Armed Forces . Motorised Rifle Regiment . The Motorised Rifle Regiment was one of the basic tactical units within the Soviet Armed Forces , totaling around 2 , 500 officers and other ranks . While normally operating as part of a Motorised Rifle Division or Tank Division , it was capable of short - term independent operations . By the late 1980s it consisted of a regimental headquarters in command of three Motorised Rifle Battalions , each numbering around five hundred personnel and equipped with either BMP infantry fighting vehicle s or BTR armoured personnel carrier s , and one Tank Battalion , typically consisting of thirty - one T - 64 , T - 72 or T - 80 tanks , although older models were present in units outside the European Theater of Operations . These were supported by a battalion of eighteen 122mm artillery pieces , either the self - propelled 2S1 Gvozdika in BMP regiments or towed D - 30 howitzer s in BTR regiments , though some BTR regiments also used the 2S1 , with additional fire support from the organic mortar battery in each infantry battalion . Additional combat support came in the form of an air defence missile and artillery company with four SA - 9 or SA - 13 s and four ZSU - 23 - 4 or 2S6 Tunguska s , an antitank missile battery with nine BRDM - mounted AT - 3 Sagger or AT - 5 Spandrel launchers , a reconnaissance company mounted on BMPs , BRDMs and motorbikes and an engineer company . Other non - combat formations included a signals company , chemical protection platoon , material support company , maintenance company , and regimental medical point . Tank Regiment . The Tank Regiment was found in both Motorised Rifle Divisions and Tank Divisions , with slight organisational differences depending between the two . By the late 1980s Tank Regiments operating as part of Motorised Rifle Divisions contained slightly over 1 , 100 officers and other ranks while those operating within Tank Divisions contained over 1 , 600 . A regimental headquarters oversaw command of three Tank Battalions of thirty - one tanks each , typically T - 64 , T - 72 or T - 80 tanks although some units used older models , and an artillery battalion of eighteen 2S1 Gvozdika self - propelled howitzers , with some using the older towed D - 30 howitzer . Tank Regiments operating as part of a Tank Division included a fifth combat battalion of motorised infantry , identical to those in BMP - equipped Motorised Rifle Regiments . Combat support and combat service support subunits were the same as in Motorised Rifle Regiments with the exception of the antitank missile battery . Artillery Regiment . The Artillery Regiment was used to provide fire support , but differed depending on whether it was part of a Motorised Rifle Division or Tank Division . The artillery regiment of an MRD consisted of three battalions of eighteen 2S3 Akatsiya s each and a battalion of eighteen BM - 21 Grad s , numbering just under 1 , 300 personnel total , while a TD artillery regiment had one less battalion of 2S3s and a little over one thousand personnel total . This was the standard model by the late 1980s , however not all artillery regiments had yet to conformed to it and one or more of the battalions might have used older weapon systems like the D - 30 howitzer . Each regiment was led by a command control battery and included an artillery reconnaissance battery , motor transport company , maintenance company , regimental medical point , chemical protection platoon and supply and service platoon . SAM Regiment . The SAM regiment was an important part of a Motorised Rifle Division or Tank Division ' s effort to envelop the battlefield in an extensive air defence network . Numbering a little over five hundred personnel total , the SAM regiment consisted of a regimental headquarters in charge of twenty SA - 6 Gainful s organised into five missile firing batteries ; most were SA - 6a platforms although since 1979 a limited number of SA - 6bs were also deployed and some regiments used the SA - 8 Gecko as an alternative . Each missile battery , along with the regimental headquarter and missile technical battery , were also equipped with three MANPAD s , either the SA - 7 Grail , SA - 14 Gremlin or SA - 16 Gimlet . Besides the missile technical battery other support subunits included an artillery reconnaissance battery , motor transport company , maintenance company and chemical protection platoon . Antiaircraft Artillery Regiment . Antiaircraft artillery ( AAA ) regiments in the late 1980s took the place of SAM regiments in divisions which were assigned to rear areas . These were equipped with twenty - four S - 60 57mm Anti Aircraft Gun s organised into four firing batteries . Each firing battery along with the regimental headquarters were also equipped with three MANPAD s , either the SA - 7 Grail , SA - 14 Gremlin or SA - 16 Gimlet . Additional subunits include a command and control battery and service battery . Irish Army . The Irish Army field artillery units are called regiments . They are divided into batteries and together the regiments form the Artillery Corps . Air Defence units are organised as a single regiment with individual batteries stationed around the country .