Through the 1930s, as Hitler’s Germany and Mussolini’s Italy grew more menacing, MI5 expanded its focus beyond what had been its almost singular efforts to counter Soviet and communist activity. Turning to the domestic fascist threat it had begun investigating in the early 1930s, Knight’s M. Section spearheaded MI5’s investigation into Britain’s fascist organisations. Generally regarded as the best agent-runner in MI5’s interwar history, if not the history of the agency as a whole, Knight earned his reputation not only from his successful penetration of the Woolwich Arsenal spy ring, but also as a result of his infiltration of fascist groups. He was no doubt aided in great part by his experiences in the political right before he joined the government to take on communist subversion and Soviet espionage. Although the fascism of the 1930s was a different beast than the fascism of the 1920s, Knight’s own previous affiliations and personal connections with some on the right made him particularly well suited to charting their activity. As the one-time Director of Intelligence for the British Fascisti (BF), he understood not only the fascist mind-set but also the mechanics of the organisations and the people involved. He first honed his skills while taking part in the right-wing movement of the 1920s. It was during that time that fascist groups had become increasingly sophisticated, as demonstrated by the development of paramilitary wings and, in some cases, intelligence branches. The British Empire Union (BEU), which had been founded during the First World War by George Makgill, provides one such example. It was linked in turn to the Industrial Intelligence Bureau (IIB) – the group in which Knight had begun his intelligence career by spying on left-wing groups before was recruited to the government.

Knight’s departure from the fascist movement and his entry into MI5 had coincided with the extreme right’s distinct movement towards anti-Semitism and eventually pro-German and pro-Italian sentiment. Yet when he left fascism to work actively against the connections of his own past, those links nonetheless provided him with a valuable pool of recruits for the agent operations he conducted after joining MI5 in 1931.