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 on the Russian Front: a German report of a Soviet attack on November 20; on the Russian Front: a German operational report of November 20; a 4th Panzer Group report of November 20; a 56th Army Corps report of November 20; a German report of progress south east of Tula on November 20; of German losses in the Moshaisk sector on November 20; of German operations on November 20; and a German Supreme Army report of November 20.