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 reports: that the Hipper and Scheer are to change berth, on May 1; the 10th Air Corps reports the result of an air raid on Port Said, on May 1; a German night fighter report for April 30-May 1; on German Air Force (GAF) operations in North Africa for May 1; an extract of a GAF report covering the Russian Front and the Far East, on May 1; on a 4th Air Fleet instruction summarising the reorganisation of the GAF, on May 1; the Japanese ambassador in Kuibyshev reports on U.S.-Soviet relations, on April 24; the Portuguese minister in Stockholm reports a suggested German approach to the U.S., on April 28; the Portuguese minister in Rome reports the closing of the German frontiers, on May 1; and the Turkish ambassador in London reports a rumour of German-Soviet negotiations, on May 1.