This section provides information about the constitutional position, function and history of the Judge Advocate General (JAG), his team of judges, and the staff who support them. It also contains a brief outline of the legal system which underlies the discipline of the British Armed Forces.


This is an informal guide to the Service justice system and is not authoritative as to the law. Service law is to be found in the statutes, statutory instruments, regulations, and reports of cases decided by the superior courts; a brief list of some of the relevant statutes is given below.

Historical Background

The conduct of English soldiers was for many centuries regulated by the Court of the High Constable and Earl Marshal. From 1521 onwards, it was the “Court of the Marshal”, and after the standing army had been brought into being in Cromwellian times the office of Judge Advocate General was created in 1666 to supervise “Courts-martial”.

It has been held in continuous succession ever since, being expanded to cover Great Britain, and later the United Kingdom, the Royal Air Force, the Royal Navy, and all British land, air and naval forces overseas. Historically the responsibilities of the Judge Advocate General were very wide and included oversight of both prosecution and defence arrangements as well as the court.

Since 1948, the role has concerned the Court-martial process. From 1661 the office of Judge Advocate of the Fleet (JAF) existed to supervise the Royal Navy Courts-martial system, separately from the JAG. The two historic offices were amalgamated by the Armed Forces Act 2006, with the role of JAF subsumed into JAG. The Armed Forces Act 2006 repealed the three Service Discipline Acts of 1955/57, established a single system of Service law, and created the Court Martial as a standing court. It came into effect on 31 October 2009.

Appointment of Judge Advocate General

The Judge Advocate General is appointed by Her Majesty the Queen by means of Letters Patent, on the recommendation of the Lord Chancellor. He is a Law Officer of the Crown and an independent member of the judiciary and is always a civilian, although he may have served in the armed forces. The JAG is not a General of the Army; the word “general” signifies broad oversight, as in Secretary-General, Attorney-General, etc. The current JAG (from November 2004) is His Honour Judge Jeff Blackett who is also a circuit judge and who formerly served in the Royal Navy.


The JAG has a team of full-time judges comprising the Vice-Judge Advocate General (Judge Michael Hunter) and six Assistant Judge Advocates General, and can also call upon the services of Deputy (part-time) Judge Advocates.

All the judges are civilians, appointed from the ranks of experienced barristers or solicitors in the same way as other District and Circuit Judges. When conducting a particular trial they are formally titled “The Judge Advocate”, and out of court they are generally referred to and addressed as “Judge”. In court the judges wear legal costume, comprising a bench wig and black gown, with a tippet (sash) in army red with navy blue and air-force blue edges.

The JAG and many Judge Advocates also sit in the Crown Court. It is also possible for a High Court Judge to be specified to preside in the Court Martial as a Judge Advocate; this is done for exceptionally serious or unprecedented cases, just as in the Crown Court.

Administrative offices

The administrative staff in the Office of the JAG (OJAG) are part of the Judicial Office, an independent body of civil servants supporting the judiciary.. The office is situated in the Thomas More Building, Royal Courts of Justice, Strand, London WC2A 2LL. OJAG staff support the judges in the exercise of their judicial functions.

The Military Court Service (MCS) is part of the Ministry of Defence, and maintains four main Military Court Centres at Colchester (Essex), Bulford (Wilts), Catterick (Yorks), and Sennelager (Germany), plus further centres at Aldergrove (N Ireland), Portsmouth (Hants), and Episkopi (Cyprus). MCS arranges, funds and supports trials at these centres and at other ad hoc venues in UK and overseas. Communications about particular cases must be addressed in the first instance to the Court Administration Officer at the MCS Headquarters in Upavon, Wilts.

Services Criminal Justice System

The main elements of the criminal justice system are:

A. The Court Martial

Serious matters, including both offences against the civilian criminal law and specifically military disciplinary offences, may be tried in the Court Martial, which is a standing court. A Judge Advocate arraigns each defendant and conducts the trial which is broadly similar to a civilian Crown Court trial in all cases, even when dealing with a minor disciplinary or criminal offence.

The jury, known as the board, comprises between three and seven commissioned officers or Warrant Officers depending on the seriousness of the case. Having listened to the Judge Advocate’s directions on the law and summary of the evidence, they are responsible for finding defendants guilty or not guilty.

Following a finding or plea of guilty, the board joins the Judge Advocate to decide on sentence. The Court Martial has the same sentencing powers in relation to imprisonment as a Crown Court, including life imprisonment. Most of the sentencing powers in the Criminal Justice Act 2003 are also available in the Court Martial.

B. Summary Hearings by a Commanding Officer

Minor disciplinary and criminal matters are deal with summarily by the Commanding Officer of the accused. The great majority of matters are disposed of in this way, which forms one of the foundations of the disciplinary system of the armed forces. A Commanding Officer has powers of punishment up to 28 days’ detention, which may be extended to 90 days’ detention with approval from Higher Authority. In all cases an accused person may elect for trial in the Court Martial rather than appear before their Commanding Officer, or may appeal to the Summary Appeal Court after the event.

C. Summary Appeal Court

The accused, if dissatisfied with the outcome of a summary hearing, always has the right of appeal to the Summary Appeal Court, which is conducted by a Judge Advocate accompanied by two officers. This is modelled on an appeal from a Magistrates’ Court to the Crown Court.

D. Court Martial Appeal Court

The avenue of appeal for a convicted defendant, subject to obtaining permission to appeal, is to the Court Martial Appeal Court (as the Court of Appeal Criminal Division is named when dealing with Service cases), and ultimately to the Supreme Court.

E. Service Civilian Court

Civilians who are officials attached to the Services overseas, or dependants of Service personnel resident overseas (for example in Germany or Cyprus) may be tried for minor offences by the Service Civilian Court (which consists of a Judge Advocate sitting alone), or, for more serious matters, may be tried in the Court Martial. This is then usually constituted with an all-civilian board acting as a jury; in such cases the Judge Advocate sentences alone.

F. Custody, Search Warrants and Arrest Warrants

If a serviceman or woman is to be detained in custody, or if private premises need to be searched in the course of investigations, or if a person needs to be arrested, the authority of a Judge Advocate is required. The JAG or one of the judges must be satisfied that the continued detention, or the search or arrest, is legally justified. Such cases are often heard by video link and a judge is on duty every day of the year to rule upon urgent applications if required.

Functions of the Judge Advocate General

The duties of the JAG include the following:

  • To act as the Presiding Judge in the Services criminal jurisdiction and leader of its judges, thereby supervising the jurisdiction
  • To provide guidance to all stakeholders in the Services criminal justice system on practices and procedures, developments and reforms
  • To monitor the workings of the Services criminal justice system and to advise on its efficiency and effectiveness
  • To be a member of the Services Justice Board
  • To specify judges to conduct specific Court Martial trials in UK or abroad
  • To provide judges to conduct Summary Appeal Courts and Standing Civilian Courts, and to rule upon applications for detention in custody and for search and arrest warrants
  • To act as the trial judge personally conducting some of the most serious, sensitive or controversial trials in the Court Martial (such as for murder)
  • To refer to the Court Martial Appeal Court cases involving a point of law of exceptional importance
  • To keep the record of proceedings for not less than six years after trial in all cases

List of selected statutes

  • Air Force Act 1955
  • Armed Forces Acts 1976, 1986, 1991, 1996, 2001, 2006, 2011
  • Army Act 1955
  • Courts and Legal Services Act 1990
  • Courts-Martial Appeal Act 1951
  • Courts-Martial (Appeals) Act 1968
  • Criminal Justice Act 2003
  • Human Rights Act 1998
  • International Criminal Courts Act 2001
  • Naval Discipline Act 1957
  • Police and Criminal Evidence Act 1984
  • Reserve Forces Act 1996

Contacting the Office of the Judge Advocate General

The administrative office forms part of the Judicial Office. OJAG staff support the judges in the exercise of their judicial functions.

The Office of the Judge Advocate General
9th Floor
Thomas More Building
London WC2A 2LL

Tel: 020 7218 8089
Fax : 020 7218 8094
Email: The Office of the Judge Advocate General

All communications by parties and their representatives about current cases are to be addressed in the first instance to:
The Military Court Service
Building 398
Trenchard Lines
Wilts SN9 6BE

Tel: 01980 618058
Fax : 01980 618060
Email: The Military Court Service

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