Permanent Under-Secretary's Department
From the time of the creation of the office of the Secretary of State for Foreign Affairs in March 1782, it was apparent that it was necessary for the Foreign Secretary to have a staff to undertake duties in his absence. The first of these was the sole Under-Secretary (William Fraser, in post 1783 to 1789), whose duties were largely clerical. However, as the business of the Foreign Office increased, especially following the introduction of telegraphic communications, two (occasionally three) Under-Secretaries were required, and they began to take on much of the work previously performed by the Foreign Secretary himself.
While the posts were held initially at the pleasure of the Foreign Secretary (i.e. they were political appointments) the benefits of continuity were appreciated, so that one of the existing Under-Secretaries was usually retained by a new Foreign Secretary. From this practice developed the office of the Permanent Under-Secretary, retaining his post regardless of the political complexion of the government in power. From 1823 the office of the Permanent Under-Secretary became the more important of the two Under- Secretaries, developing into the office of the professional head of the Office, while the other Under-Secretaryship became more involved with parliamentary business.
The responsibilities of the Permanent Under-Secretary developed to include being the head of the Foreign Service, chief adviser to the Foreign Secretary, receiving foreign ambassadors on the Foreign Secretary's behalf, chairing the Foreign Office senior promotions board and advising on major appointments, being accounting officer, and being in general charge of the administration of the Foreign Office. The Permanent-Under Secretary was also given responsibility for administering the secret vote (for which from 1825 he was paid a fixed annual honorarium) for the purpose of collecting intelligence about the activities of foreign powers that were of interest to the Crown.
The Permanent Under-Secretary's Department (PUSD) was established in 1949 and continued throughout the post-war period, and beyond the merger of the Foreign Office (FO) with the Commonwealth Office to become the Foreign and Commonwealth Office (FCO) in 1968.
As the volume of business passing through the Foreign Office steadily increased and more political departments were created, the activities of the Permanent Under-Secretary's Department became more specialised. Eventually, the functions of the department centred on planning, liaison with the armed services, Chiefs of Staff and the responsible departments and ministries, defence policy, intelligence functions and such miscellaneous functions as the exchange of scientific information (particularly atomic and nuclear technology).
In 1966, following the creation of the Ministry of Defence, the department was split in two. A new Defence Department was created to undertake liaison with the Ministry and the armed services, and also to conduct business relating to defence supplies. The Permanent Under-Secretary's Department continued to undertake intelligence functions, including liaison with the Joint Intelligence Committee and the Defence Intelligence Staff.
For a greater part of the post war period in the 20th Century the superintending Under-Secretary for PUSD also served as Chairman of the Joint Intelligence Committee (JIC) and that role is reflected in significant body of the department's records.
Until 1872, legal advice on all matters to the Foreign Office was supplied by the office of HM Advocate General. In 1872, this office was allowed to lapse upon falling vacant and its functions were transferred, general legal advice on international matters passing to the Foreign Office. Initially, one under secretary in the Foreign Office was responsible for the provision of legal advice, and in 1882 when the responsible officer at the time was promoted to Permanent Under Secretary, the responsibility moved with him. A Legal Assistant was appointed in 1886, reporting directly to the Permanent Under Secretary.
From 1892 holder of this post was known as the Legal Adviser. Further assistant legal adviser posts were created in 1902, 1914 and 1925, and in 1929 one of these assistant legal advisers was given specific responsibility for claims matters. By 1955 there were six assistant legal advisers, and by the time of the merger of the Foreign Office with the Commonwealth Office the legal adviser was assisted by a team of eleven deputies, counsellors and assistants, and had an administrative assistant and a librarian in charge of the legal library.
The legal adviser and his staff have never formed a functional department of the Foreign Office, but instead have offered legal advice to the departments of the Office as required, while remaining responsible to the Permanent Under Secretary. The legal advisers' duties include offering advice on matters of English and international law, assisting in the drafting of treaties and instruments, attending conferences as part of United Kingdom delegations, and assisting in the presentation of the United Kingdom government's cases to the International Court of Justice in The Hague and elsewhere.