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 contains a message from C to the Assistant Chief of Air Staff Intelligence (ACASI) with the Prime Minister's (PM's) comment on 2265/T4; a German Air Force (GAF) report on Allied air raids on Germany, from March 7; and the Chief of the Air Staff's (CAS's) reply on the coversheet, on March 15.