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 Director of Military Intelligence (DMI) for the Chief of the Imperial General Staff (CIGS) and the Chief of the Air Staff (CAS) on instruction from the Prime Minister (PM); and the following report on South-eastern Europe: a report from the German Air Force (GAF) Command for the South-East on October 6 on the availability of aircraft for convoy escort duties in the Adriatic.