Defence Officials Ran Secret Bio-Warfare Field Trials for 13 Years
By June Hargrove ·
Secret biological warfare field trials ran for 13 years, with technical reports on the organisms involved feeding a chain of command up to the Minister's office.
Porton Down sits on 7,000 acres of Wiltshire countryside, just north-east of the village of Porton. According to the public record, this site has served as a science and defence technology campus for over a century, housing the Ministry of Defence's Defence Science and Technology Laboratory. It is a place defined by its secrecy, known for military research that often skirts the edge of public comfort.
Within the UK National Archives, a specific series of records provides a window into the technical operations of this campus during the early Cold War. The file's catalogue entry records a series designated as DEFE 55, titled "Ministry of Defence and predecessors: Microbiological Research Establishment and predecessors: Reports and Technical Papers."
A Wiltshire Campus
The records in DEFE 55 cover a thirteen-year span, beginning in 1946 and ending in 1959. The catalogue entry notes that the series contains reports from two distinct iterations of the facility: the Microbiological Research Department, which operated from 1946 to 1957, and the Microbiological Research Establishment, which took over from 1957 to 1959.
The mandate for these two entities was explicit. The catalogue records that they were "responsible for assessing the biological warfare threat, devising means of protection and detection and studying the organisms involved."
For a radar officer, "detection" is a familiar term—it is the act of identifying a signature against a background of noise. In the context of biological warfare, however, detection involves the identification of microscopic agents, often designed to be invisible and odorless. The scope of the work at Porton Down was not merely defensive; it required a deep understanding of the "organisms involved" to know what a threat would look like if it ever arrived on British soil.
Field Trial Reports
The most concrete detail in the catalogue description is the nature of the materials currently held in the series. The entry specifies that DEFE 55 contains "development notes and field trial reports."
Field trials are where laboratory theory meets geography. In the realm of microbiological research, a field trial typically involves the release of a biological agent into a controlled environment to study its dispersal, persistence, and effect. The catalogue does not name the organisms used in these trials, nor does it specify the locations of the tests beyond the general association with the Porton Down campus and its surrounding interests. It simply records that these reports exist.
There is another detail in the catalogue that suggests the facility's reach extended beyond the Ministry of Defence. The entry notes that the Microbiological Research Establishment "also used its specialised facilities in aid of various civil organisations." The record does not specify which organisations were aided or what the nature of that assistance entailed. Whether this involved public health crises or the study of agricultural pests remains unstated in the catalogue description.
DEFE 13/287 and the Policy Loop
Technical reports like those in DEFE 55 do not exist in a vacuum. They are the raw data that feed higher-level decision-making. The National Archives' catalogue shows a network of related files that place the technical work of the Microbiological Research Establishment within a broader political framework.
For instance, file DEFE 13/287 is titled "Biological warfare: research and development" and sits within the Registered Files of the Minister's Office. While DEFE 55 contains the "technical papers," DEFE 13/287 represents the point where that research reached the desk of the Minister.
The policy loop continues through other records. File DEFE 7/2100 refers to the "Defence Research Policy Committee: biological warfare," and DEFE 7/1964 mentions the "Defence Research Policy Staff." Perhaps most telling is DEFE 23/293, which contains files on biological and chemical warfare research and development held by the Permanent Under Secretary of State for Defence.
When viewed together, these catalogue entries describe a vertical hierarchy. At the bottom is the technical work—the study of organisms and the conduct of field trials recorded in DEFE 55. Above that are the policy committees and the staff officers. At the top are the registered files of the Minister and the Permanent Under Secretary. The technical reports provided the evidence; the policy files provided the direction.
The catalogue for DEFE 55 stops where the documents begin. It tells us that development notes and field trial reports were produced between 1946 and 1959, but it does not list the specific pathogens tested or the results of the trials. It leaves the reader with the knowledge that a system for biological detection and protection was being built in Wiltshire, supported by a chain of command that reached the highest offices of the British defence establishment.