MI8

MI8, or Military Intelligence, Section 8 was a British Military Intelligence group responsible for signals intelligence and was created in 1914. It originally consisted of four sections: MI8(a), which dealt with wireless policy; MI8(b), based at the General Post Office, dealt with commercial and trade cables; MI8(c) dealt with the distribution of intelligence derived from censorship; and MI8(d), which liaised with the cable companies. During World War I MI8 officers were posted to the cable terminals at Poldhu Point and Mullion in Cornwall and Clifden in County Galway, continued until 1917 when the work was taken over by the Admiralty. In WW2, MI8 was responsible for the extensive War Office Y Group and briefly, for the Radio Security Service.

MI8 was the signals intelligence department of the War Office that ran a worldwide Y station network. Additionally, for an 18-month period, from late 1939 to mid 1941, it also ran the Radio Security Service, under the designation of MI8c, but this was quickly handed over to MI6. The remainder of this page relates only to this small organisation, with, regrettably, no information concerning the major role of MI8.

The Radio Security Service evolved from the Illicit Wireless Intercept Organisation (IWIO), which was given the designation MI1g and run by Lt Col. J S Yule. From an office in Broadway, IWIO collaborated with Military Intelligence, Section 5 (MI5) and with the General Post Office (GPO) to set up and control a small network of Direction Finding (DF) and intercept stations, to locate illicit transmissions inside Britain. Col Yule also made detailed plans for similar networks in British overseas territories, before IWIO evolved into RSS in September 1939.

But Lt Col Adrian Simpson developed a proposal which stated that a small number of stations, located around Britain, would not work.

At the start of World War II, Vernon Kell, the head of MI5, introduced a contingency plan to deal with the problem of illicit radio transmissions. A new body was created, the Radio Security Service (RSS), headed by Major J.P.G. Worlledge. Until 1927, Worlledge had commanded a Wireless Company in Palestine. His brief was to "intercept, locate and close down illicit wireless stations operated either by enemy agents in Great Britain or by other persons not being licensed to do so under Defence Regulations, 1939". As a security precaution, RSS was given the cover designation of MI8(c).

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