Government Code and Cypher School: Signals Intelligence Passed to the Prime Minister, Messages and Correspondence

A file of signals intelligence reports, messages, and correspondence issued by the Government Code and Cypher School and sent by the head ('C') of the Secret Intelligence Service (MI6) to the Prime Minister, Winston Churchill. This file includes the following correspondence: C's note to the Prime Minister (PM) accompanying two items from the Chief of the Air Staff (CAS) in answer to the PM's queries on reference numbers 2266/T20 and 2271/T18; C's cover note only is included; both items and the CAS's comments are not included.