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: aircraft reconnaissance reports of Soviet movements in the vicinity of the 2nd Panzer Army, on March 2; of further Soviet advances; and a map illustrating the Axis and Soviet positions at this time supplied by the Chief of the Imperial General Staff (CIGS).