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: Naval Headlines, covering convoy and submarine activities in the Mediterranean; the Japanese minister in Sofia reports that Bulgarian troops are to remain in the Balkans to maintain law and order, on April 4; the Turkish minister in Budapest reports a rumour of impending German pressure on Turkey to clarify her position, on April 2; the Turkish ambassador in Rome reports the Hungarian denial of a rumoured Bulgaria-Hungary alliance, on April 6; and the Turkish ambassador in Kuibyshev repeats Japanese information about a German offensive against Russia, on April 5.