British Armed Forces The British Armed Forces form the military of the United Kingdom , tasked with defence of the country , its overseas territories and the Crown dependencies ; as well as promoting the UK ' s wider interests , supporting international peacekeeping efforts , and providing humanitarian aid . They consist of the Royal Navy , a blue - water navy with a fleet of 77 commissioned ships , the Royal Marines , a highly specialised amphibious light infantry force , the British Army , the UK ' s principle land warfare branch , and the Royal Air Force , a technologically sophisticated air force with a diverse operational fleet consisting of both fixed - wing and rotary aircraft . The Commander - in - chief of the British Armed Forces is the British monarch , Queen Elizabeth II , to whom members of the forces swear allegiance . However the British parliament maintains the armed forces during times of peace with the passing of quinquennial armed forces acts . The armed forces are managed by the Defence Council of the Ministry of Defence , headed by the Secretary of State for Defence . The UK is an active and regular participant in NATO and other coalition operations . The country is also party to the Five Power Defence Arrangements . Recent operations have included wars in Afghanistan and Iraq , the 2000 intervention in Sierra Leone , peacekeeping responsibilities in the Balkans and Cyprus , and participation in the UN - mandated no - fly zone over Libya . Overseas garrisons and facilities are maintained at Ascension Island , Belize , Brunei , Canada , Diego Garcia , the Falkland Islands , Germany , Gibraltar , Kenya , Qatar and Cyprus . The United Kingdom tested its first nuclear weapon under Operation Hurricane in 1952 , becoming the third nation in the world to achieve the status of a nuclear power . , Britain remains one of five recognised nuclear powers , with a total of 225 nuclear warheads . Of those , no more than 160 are deployed and active . Its nuclear deterrence system is based on Trident missiles on board ballistic missile submarine s . History . Upon the Act of Union in 1707 , the armed forces of England and Scotland were merged into the armed forces of the Kingdom of Great Britain . By 1815 , with the defeat of Napoleon at the Battle of Waterloo Britain had risen to become the world ' s dominant superpower , and the British Empire subsequently presided over a period of relative peace , known as Pax Britannica , until the outbreak of World War I in 1914 . Between 1707 and 1914 , British forces played a prominent role in notable conflicts including the Seven Years ' War , the Napoleonic Wars and the Crimean War . The current structure of defence management in Britain was set in place in 1964 when the modern day Ministry of Defence ( MoD ) was created ( an earlier form had existed since 1940 ) . The MoD assumed the roles of the Admiralty , the War Office and the Air Ministry . Cold War . Post – World War II economic and political decline , as well as changing attitudes in British society and government , were reflected by the Armed Forces ' contracting global role . Britain ' s protracted decline was dramatically epitomised by its political defeat during the Suez War of 1956 . The 1957 Defence White Paper abolished conscription and reduced the size of the Armed Forces from 690 , 000 to 375 , 000 by 1962 . Seeking an inexpensive alternative to maintaining a large conventional military , the government pursued a doctrine of nuclear deterrence . This initially consisted of free - fall bombs operated by the RAF , but these were eventually superseded by the submarine - launched Polaris ballistic missile . While assurances had been made to the United States that Britain would maintain a presence " East of Suez " , a process of gradual withdrawal from its eastern commitments was undertaken in the 1960s , primarily for economic reasons . By the mid - 1970s , Britain had withdrawn permanently deployed forces from Aden , Bahrain , Malaysia , Mauritius , Oman , Sharjah , and Singapore . Agreements with Malta ( expired 1979 ) and South Africa ( terminated 1975 ) also ended . With a permanent presence east of Suez effectively reduced to Hong Kong ( up to 1997 ) and Brunei , the Armed Forces reconfigured to focus on the responsibilities allocated to the services during the Cold War . Substantial forces thus became committed to NATO in Europe and elsewhere ; by 1985 , 72 , 929 personnel were stationed in Continental Europe . The British Army of the Rhine and RAF Germany consequently represented the largest and most important overseas commitments that the British Armed Forces had during this period . The Royal Navy ' s fleet developed an anti - submarine warfare specialisation , with a particular focus on countering Soviet submarines in the Eastern Atlantic and North Sea . In the process of this transition and due to economic constraints , four conventional aircraft carriers and two " commando " carriers were decommissioned between 1967 and 1984 . With the cancellation of the CVA - 01 project , three " Invincible " - class STOVL aircraft carriers , originally designed as " Through - Deck Cruisers " , became their ultimate replacements . While this focus on NATO obligations increased in prominence during the 1970s , low - intensity conflicts in Northern Ireland and Oman emerged as the primary operational concerns of the British Armed Forces . These conflicts had followed a spate of insurgencies against British colonial occupation in Aden , Cyprus , Kenya and Malaysia . An undeclared war with Indonesia had also occurred in Borneo during the 1960s , and recurring civil unrest in the declining number of British colonies often required military assistance . Recent history . Four major reviews of the British Armed Forces have been conducted since the end of the Cold War . All three services experienced considerable reductions in manpower , equipment , and infrastructure during this period while re - structuring to deliver a greater focus on expeditionary warfare . The Conservative government produced the Options for Change review in the 1990s , seeking to benefit from a perceived post – Cold War " peace dividend " . Though the Soviet Union had disintegrated , a presence in Germany was retained in the reduced form of British Forces Germany . Experiences during the First Gulf War prompted renewed efforts to enhance joint operational cohesion and efficiency among the services by establishing a Permanent Joint Headquarters in 1996 . An increasingly international role for the British Armed Forces was pursued since the Cold War ' s end . This entailed the Armed Forces often constituting a major component in peacekeeping missions under the auspices of the United Nations or NATO , and other multinational operations . Consistent under - manning and the reduced size of the Armed Forces highlighted the problem of " overstretch " during the conflicts in Iraq and Afghanistan . This reportedly contributed to personnel retention difficulties and challenged the military ' s ability to sustain its overseas commitments . A Strategic Defence Review ( SDR ) — described as " foreign - policy - led " — was published in 1998 . Expeditionary warfare and tri - service integration were central to the review , which sought to improve efficiency and reduce expenditure by consolidating resources . Most of the Armed Forces ' helicopters were collected under a single command and a Joint Force Harrier was established in 2000 , containing the Navy and RAF ' s fleet of Harrier Jump Jet s . A Joint Rapid Reaction Force was formed in 1999 , with significant tri - service resources at its disposal . The first major post - 11 September restructuring was announced in the 2004 Delivering Security in a Changing World : Future Capabilities review , continuing a vision of " mobility " and " expeditionary warfare " articulated in the SDR . Future equipment projects reflecting this direction featured in the review , including the procurement of two large aircraft carriers and a series of medium - sized vehicles for the Army . Reductions in manpower , equipment , and infrastructure were also announced . The decision to reduce the Army ' s regular infantry to 36 battalions ( from 40 ) and amalgamate the remaining single - battalion regiments was controversial , especially in Scotland and among former soldiers . Envisaging a rebalanced composition of more rapidly deployable light and medium forces , the review announced that a regiment of Challenger 2 main battle tank s and a regiment of AS - 90 self - propelled artillery would be converted to lighter roles . There were more than 30 , 000 members of the British Armed Forces deployed abroad in January 2007 , serving in various capacities . Peacekeeping , humanitarian aid , and disaster relief tasks increased in the 2000s , many under the auspices of the United Nations and NATO . The Armed Forces contributed to the international humanitarian and reconstruction efforts in the aftermath of the 2004 tsunami and 2005 earthquake in Pakistan . Within the United Kingdom , there were approximately 140 , 000 personnel stationed in England , 13 , 200 in Scotland , 7 , 000 in Northern Ireland , and 6 , 200 in Wales . The conflict in Northern Ireland had required the Armed Forces to provide " Military aid to the civil power " from 1969 , with a presence that peaked at over 20 , 000 regular personnel in 1972 . Sectarian and paramilitary violence subsided after the Good Friday Agreement was signed in 1998 . and the IRA declared an end to its campaign in 2005 . Operational support for the Police Service of Northern Ireland , known as Operation Banner , officially ended on 1 August 2007 , resulting in the reduction of the military presence to the size of a peacetime garrison . As a result of the Strategic Defence and Security Review conducted in October 2010 , Prime Minister David Cameron signed a 50 - year treaty with French President Nicolas Sarkozy that would have the two countries cooperate intensively in military matters . Today . The British Armed Forces is a professional force with a strength in September 2014 of 162 , 550 Regular and 28 , 860 Volunteer Reserve personnel . This gives a total strength of 191 , 410 Service Personnel . In addition , all ex - Regular personnel retain a " statutory liability for service " and are liable to be recalled ( under Section 52 of the Reserve Forces Act ( RFA ) 1996 ) for duty in a time of need , this is known as the Regular Reserve . However , MoD publications since April 2013 no longer report the entire strength of the Regular Reserve , instead they only give a figure for Regular Reserves who serve under a fixed - term reserve contract . These contracts are similar in nature to those of the Volunteer Reserve . As of 2014 , regular Reserves serving under a fixed - term contract numbered 45 , 110 personnel . All personnel figures exclude the Military Provost Guard Service and the University Training Units ; the University Royal Naval Unit , the Officers ' Training Corps and the University Air Squadron . Britain has the fifth or sixth - largest defence budget in the world , with the country spending more than countries like Germany or Japan but more or less comparable to that of France or Saudi Arabia . In September 2011 , according to the Royal United Services Institute , current " planned levels of defence spending should be enough for the United Kingdom to maintain its position as one of the world ' s top military powers , as well as being one of NATO - Europe ' s top military powers . Its edge – not least its qualitative edge – in relation to rising Asian powers seems set to erode , but will remain significant well into the 2020 ’ s , and possibly beyond . " In the 2013 Spending Review , the Chancellor of the Exchequer , George Osborne , reinforced the government ' s commitment to the 2010 SDSR and stated the £38bn " black hole " in the defence budget had been filled , that at over 2 % of GDP , the defence budget will remain one of the largest in the world , the equipment budget will grow by 1 % in real terms every year after 2015 , that there will be further reductions in the civilian MoD workforce , PFI contracts signed in the last decade would be renegotiated , the way equipment is purchased is to be overhauled , and a greater commitment to cyber warfare . Command organisation . As Sovereign and head of state , Queen Elizabeth II is Head of the Armed Forces and their Commander - in - Chief . Long - standing constitutional convention , however , has vested " de facto " executive authority , by the exercise of Royal Prerogative powers , in the Prime Minister and the Secretary of State for Defence , and the Prime Minister ( acting with the support of the ) makes the key decisions on the use of the armed forces . The Queen , however , remains the " ultimate authority " of the military , with officers and personnel swearing allegiance to the monarch . It has been claimed that this includes the power to prevent unconstitutional use of the armed forces , including its nuclear weapons . The Ministry of Defence is the Government department and highest level of military headquarters charged with formulating and executing defence policy for the Armed Forces ; it currently employs over 60 , 000 civilians as of 2014 . This number will be reduced to just 55 , 000 by 2015 ( a reduction of 25 , 000 as per the October 2010 SDSR ) and then again to 48 , 000 by 2020 . The department is controlled by the Secretary of State for Defence and contains three deputy appointments : Minister of State for the Armed Forces , Minister for Defence Procurement , and Minister for Veterans ' Affairs . Responsibility for the management of the forces is delegated to a number of committees : the Defence Council , Chiefs of Staff Committee , Defence Management Board and three single - service boards . The Defence Council , composed of senior representatives of the services and the Ministry of Defence , provides the " formal legal basis for the conduct of defence " . The three constituent single - service committees ( Admiralty Board , Army Board and Air Force Board ) are chaired by the Secretary of State for Defence . The Chief of the Defence Staff is the professional head of the Armed Forces and is an appointment that can be held by an Admiral , Air Chief Marshal or General . Before the practice was discontinued in the 1990s , those who were appointed to the position of CDS had been elevated to the most senior rank in their respective service ( a 5 - star rank ) . The CDS , along with the Permanent Under Secretary , are the principal advisers to the departmental minister . The three services have their own respective professional chiefs : the First Sea Lord , the Chief of the General Staff and the Chief of the Air Staff . Personnel are based in a number of overseas territories , though internal security for the majority is provided solely by small police forces . Garrisons and facilities exist in Ascension Island , Diego Garcia , the Falkland Islands , Gibraltar , and the Sovereign Base Areas in Cyprus . These deployments accounted for over 5 , 000 personnel in 2006 . Locally - raised units are maintained in Bermuda ( The Bermuda Regiment ) , the Falkland Islands ( Falkland Islands Defence Force ) , and Gibraltar ( Royal Gibraltar Regiment ) . Though their primary mission is " home defence " , individuals have volunteered for operational duties . The Royal Gibraltar Regiment has recently mobilised section - sized units for attachment to regiments deployed to Iraq . Weapons of mass destruction . The United Kingdom is one of only five recognised nuclear weapon states under the Non - Proliferation Treaty and maintains an independent nuclear deterrent , currently consisting of four " Vanguard " - class ballistic missile submarine s . This is known as the UK Trident programme and delivers a ' continuous at sea deterrent ' capability . Nomenclature of the UK deterrent is after the UGM - 133 Trident II submarine - launched ballistic missile that is used to deliver the nuclear warheads . Estimates of the United Kingdoms nuclear stockpile put it at approximately 225 nuclear warheads in total , with 160 of those being active . A successor programme is currently in its early stages with a final decision to be made in 2016 after the 2015 general election . It primarily seeks to replace the " Vangaurd " - class submarines with a new generation of SSBNs , however , the programme will also extend the life of the UGM - 133 Trident II ballistic missiles , refurbish the nuclear warheads and modernise existing infrastructure associated with the deterrent . Former weapons of mass destruction possessed by the United Kingdom include both biological and chemical weapon s . These were renounced in 1956 and subsequently destroyed . UK Joint Expeditionary Force . The UK Joint Expeditionary Force , not to be confused with the similarly named UK - French Combined Joint Expeditionary Force , was announced in December 2012 by the Chief of the Defence Staff , General Sir David Richards . It is designed to be an integrated joint force , with capabilities across the spectrum at sea , on land and in the air , with the aspiration being greater levels of integration than previously achieved especially when combined with other nations ' armed forces . Of variable size , it is intended to be the basis of all the UK armed forces ' combined joint training ; a framework into which other nations will fit . It will be the core of the UK ' s contribution to any military action , whether NATO , coalition or independent . Together with Command and Control elements including HQ Allied Rapid Reaction Corps and the maritime component HQ at Northwood , the force is designed to meet the UK ' s obligations to NATO . Royal Navy . The Royal Navy is a technologically sophisticated naval force , consisting of 77 commissioned ships and around 150 aircraft . Command of deployable assets is exercised by the Fleet Commander of the Naval Service . Personnel matters are the responsibility of the Second Sea Lord / Commander - in - Chief Naval Home Command , an appointment usually held by a vice - admiral . The Surface Fleet consists of helicopter carriers , destroyer s , frigate s , amphibious assault ship s , patrol ships , mine - countermeasures , and miscellaneous vessels . The Surface Fleet has been structured around a single fleet since the abolition of the Eastern and Western fleets in 1971 . The recently built Type 45 destroyer s are technologically advanced air - defence destroyers . The Royal Navy is building two " Queen Elizabeth " class aircraft carriers , embarking an air - group including the advanced fifth - generation multi - role fighter , the F - 35B . A submarine service has existed within the Royal Navy for more than 100 years . The Submarine Service ' s four " Vanguard " - class nuclear - powered submarines carry Lockheed Martin ' s Trident II ballistic missiles , forming the United Kingdom ' s nuclear deterrent . The service possessed a combined fleet of diesel - electric and nuclear - powered submarines until the early 1990s . Following the Options for Change defence review , the Upholder class diesel - electric submarines were withdrawn and the attack submarine flotilla is now exclusively nuclear - powered . Seven " Astute " class nuclear - powered attack submarines have been ordered , with two completed , and four under construction . The " Astute " class are the most advanced and largest fleet submarines ever built for the Royal Navy , and will maintain Britain ' s nuclear - powered submarine fleet capabilities for decades to come . Royal Marines . The Royal Marines are the Royal Navy ' s amphibious troops . Consisting of a single manoeuvre brigade ( 3 Commando ) and various independent units , the Royal Marines specialise in amphibious , arctic , and mountain warfare . Contained within 3 Commando Brigade are three attached army units ; 1st Battalion , The Rifles , an infantry battalion based at Beachley Barracks near Chepstow ( from April 2008 ) , 29 Commando Regiment Royal Artillery , an artillery regiment based in Plymouth , and 24 Commando Regiment Royal Engineers . The Commando Logistic Regiment consists of personnel from the Army , Royal Marines , and Royal Navy . British Army . The British Army is made up of the Regular Army and the Army Reserve . The army has a single command structure based at Andover and known as " Army Headquarters " . Deployable combat formations consist of two divisions ( 1st Armoured and 3rd Mechanised ) and eight brigades . Within the United Kingdom , operational and non - deployable units are administered by three regionally - defined " regenerative " divisions ( 2nd , 4th , and 5th ) and London District . The Army has 50 battalions ( 36 regular and 14 territorial ) of regular and territorial infantry , organised into 17 regiments . The majority of infantry regiments contains multiple regular and territorial battalions . Modern infantry have diverse capabilities and this is reflected in the varied roles assigned to them . There are four operational roles that infantry battalions can fulfil : air assault , armoured infantry , mechanised infantry , and light role infantry . Regiments and battalions e . g . : the Parachute Regiment , exist within every corps of the Army , functioning as administrative or tactical formations . Armoured regiments are equivalent to an infantry battalion . There are 11 armoured regiments within the regular army , of which six are designated as " Armoured " and five as " Formation Reconnaissance " . With the exception of the Household Cavalry , armoured regiments and their Territorial counterparts are grouped under the Royal Armoured Corps . Arms and support units are also formed into similar collectives organised around specific purposes , such as the Corps of Royal Engineers , Army Air Corps and Royal Army Medical Corps . Royal Air Force . The Royal Air Force has a large operational fleet that fulfils various roles , consisting of both fixed - wing and rotary aircraft . Frontline aircraft are controlled by Air Command , which is organised into three groups defined by function : 1 Group ( Air Combat ) , 2 Group ( Air Support ) and 22 Group ( training aircraft and ground facilities ) . In addition 83 Expeditionary Air Group directs formations in the Middle East . Deployable formations consist of Expeditionary Air Wings and squadrons — the basic unit of the Air Force . Independent flights are deployed to facilities in Afghanistan , the Falkland Islands , Iraq , and the United States . The Royal Air Forces operates multi - role and single - role fighters , reconnaissance and patrol aircraft , tankers , transports , helicopters , unmanned aerial vehicles , and various types of training aircraft . Ground units are also maintained by the Royal Air Force , most prominently the RAF Police and the Royal Air Force Regiment ( RAF Regt ) . The Royal Air Force Regiment essentially functions as the local ground defence force of the RAF . Roled principally as ground defence for RAF facilities , the regiment contains nine regular squadrons , supported by five squadrons of the Royal Auxiliary Air Force Regiment . By March 2008 , the three remaining " Air Defence " squadrons had disbanded or re - roled and their responsibilities transferred to the British Army ' s Royal Artillery . Civilian agencies of the Ministry of Defence . The British Armed Forces are supported by civilian agencies owned by the MoD . Although they are civilian , they play a vital role in supporting Armed Forces operations , and in certain circumstances are under military discipline . Royal Fleet Auxiliary . The 13 ships of the Royal Fleet Auxiliary ( RFA ) primarily serve to replenish Royal Navy warships at sea , and also augment the Royal Navy ' s amphibious warfare capabilities through its three vessels . It is manned by 1 , 850 civilian personnel and is funded and run by the Ministry of Defence . UK Hydrographic Office . For more Information about Civilian Agencies of or within the MoD see Ministry of Defence ( United Kingdom ) . Recruitment . All three services of the British Armed Forces recruit primarily from within the United Kingdom , although citizens from the Commonwealth of Nations and the Republic of Ireland are equally eligible to join . The minimum recruitment age is 16 years ( although personnel may not serve on armed operations below 18 years ) ; the maximum recruitment age depends whether the application is for a regular or reserve role ; there are further variations in age limit for different corps / regiments . The normal term of engagement is 22 years ; however , the minimum service required before resignation is 4 years , plus , in the case of the Army , any service person below the age of 18 . At present , the yearly intake into the armed forces is 11 , 880 ( per the 12 months to 31 March 2014 ) . Excluding the Brigade of Gurkhas and the Royal Irish Regiment , as of 1 April 2014 there are approximately 11 , 200 Black and Minority Ethnic ( BME ) persons serving as Regulars across the three service branches - of those , 6 , 610 were recruited from outside the United Kingdom . In total , Black and Minority Ethnic persons represent 7 . 1 % of all service personnel , an increase from 6 . 6 % in 2010 . Women have been integrated into the British Armed Forces since the early 1990s ; however , they remain excluded from primarily combat units in the Army , Royal Marines , and Royal Air Force Regiment . As of the 1 April 2014 , there are approximately 15 , 840 women serving in the Armed Forces , representing 9 . 9 % of all service personnel . The first female military pilot was Flight Lieutenant Julie Ann Gibson while Flight Lieutenant s Jo Salter and Kirsty Moore were the first fast - jet pilots , the former flying a Tornado GR1 on missions patrolling the then Northern Iraqi No - Fly Zone . Flight Lieutenant Juliette Fleming and Squadron Leader Nikki Thomas recently were the first Tornado GR4 crew . While enforcing the Libyan No - Fly Zone , Flight Lieutenant Helen Seymour was identified as the first female Eurofighter Typhoon pilot . As of August 2011 , it was announced that a female Lieutenant Commander , Sarah West , will command the frigate HMS Portland . Since the year 2000 , sexual orientation has not been a factor considered in recruitment , and homosexuals can serve openly in the armed forces . All branches of the forces have actively recruited at Gay Pride events . The forces keep no formal figures concerning the number of gay and lesbian serving soldiers , saying that the sexual orientation of personnel is considered irrelevant and not monitored .