Foreign Office reforms instituted in 1905 brought in a central registry and sub-registry to provide a better control of its papers. From 1906, correspondence was numbered on arrival, and then placed in numbered files, arranged in five categories (one geographical and four subject) rather than all by geographical area. These categories all shared a single card index. Each country had its own country code, composed of a unique stem number, to which could be added an extra digit. This was done to indicate the category (now series) in which the papers were placed. For example, Abyssinia had number 1 for its stem number, so references to Abyssinia in the card index have the following country codes.
|Code (for Abyssinia)||1||101||201||301||401|
|Series||FO 371||FO 368||FO 369||FO 372||FO 367|
2. The country code stem numbers
|Stem code||Country||Stem code||Country||Stem code||Country|
|3||Austria||19||Greece||35||Peru (including Bolivia and Ecuador)|
|4||Belgium and Congo||20||Hayti [Haiti] and San Domingo||36||Portugal|
|5||Borneo (to 1907)||21||Hungary||37||Roumania [Romania]|
|13||Crete||29||Netherlands||45||United States of America|
|16||Egypt||32||Panama and Costa Rica||48||Zanzibar|
3. The card index
To find correspondence, use the original Foreign Office card index in the Open Reading Room at The National Archives. This is an index to the original paper numbers, which then have to be matched up to the file number by using the registers in FO 566, before converting that file number into a modern National Archives reference.
The card index is arranged by year and then by subject, name or place. It does not include the names of officials and ministers dealing with the correspondence. You may have to do some lateral thinking to find your way around the subject index terms used. However, not all documents noted in the card index and registers have survived.
Some subject headings in the card index are prefaced by cross- references to other subject headings. These are useful for tracing relevant material and, occasionally, copies of documents which have not survived elsewhere. Sample index cards are shown below: note the country code and paper number.
Step 1: Understanding the cards
|30||39806||06||Area claimed by Spitzbergen Mining and Exploration Syndicate|
[Country code 30 = FO 371, Norway] [paper no = 39806]
|145||20169||08||Contract for waterworks at ..|
[Country code 145 = FO 368, USA] [paper no = 20169]
|Club English at Zanzibar|
[Country code 448= FO 367, Zanzibar] [paper no = 11503]
|206||13881||08||Tour in states of Amazonas and Para sanctioned|
[Country code 206 = FO 369, Brazil] [paper no = 13881]
Step 2: FO 566 and the lists
To find the number of the file with which the paper was kept you need to consult the appropriate general register of correspondence in FO 566. In Procat or the hard copy catalogue this series is arranged first by country, then date, then category (diplomatic, consular, commercial, treaty, or Africa). Some of the registers are on open access in the Open Reading Room: others are ordered as original documents. Get the register you want, and find the appropriate date cut. To find the paper number, look in the column second from left on the left hand page. Then check the number in the 'kept with' column on the right, which indicates the file with which the paper was kept.
Step 3: The modern reference
FO 566 register entries often provide cross-references to related material. Left hand pages of registers refer to incoming correspondence and right hand pages to outgoing. Entries in black in the 'forward reference' file refer to incoming correspondence numerically arranged on the left page. Entries in red usually refer to outgoing correspondence arranged numerically on the right page. The file number can then be traced to a document reference as in step two.
5. Other series
Further relevant material may be obtained from record series FO 370 (Library) and FO 366 (Chief Clerk). These series are not included in the card index. This also applies to a number of series containing Embassy and Consular archives, Confidential Print and miscellaneous series. Material gathered in cases (bundles of related material) may appear out of sequence in the series lists and a consolidated index to these cases is available in the Open Reading Room.
6. Further reading
L Atherton, 'Never Complain, Never Explain', Records of the Foreign Office and State Paper Office 1500-c.1960, Public Record Office Readers' Guide No. 7 (PRO publications, 1994)
The Records of the Foreign Office, 1782-1939, Public Record Office Handbooks No. 13 (HMSO, 1969)
Michael Roper, The Records of the Foreign Office, 1782-1968 (Public Record Office Publications 2002)