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 messages: the First Sea Lord's (ISL's) reply to the Prime Minister's (PM's) query on an item in the Naval Headlines attached; a report of a night raid on Alexandria harbour on April 7 by aircraft from Crete; a 10th Air Corps report of photographic reconnaissance on Alexandria, on April 6; a 10th Air Corps report of photographic reconnaissance on Famagusta on April 6; a Naval Headlines report on U-boat activities in the north Atlantic and Barents Sea; that Gneisnau is under way in the Baltic on April 5; and that Luetzow is in Swinemuende until the ice clears; the Italians report the British hospital ship Somersetshire sinking off Mersa Matruh; and a further Naval Headlines report on the activities of U-boats awaiting the Murmansk convoy; and on Italian convoy activities.