'C', Chief of the Secret Intelligence Service (SIS): Relations Between Foreign Office Staffs Abroad and C's Organisation

A file of correspondence involving 'C', chief of the Secret Intelligence Service (MI6), concerning leakage of information and relations with foreign governments. The letters discuss the implications for foreign relations of two cases; the first involves the deliberate leakage of a document detailing Portuguese collaboration with the allies to establish the worth of an agent inserted into the German intelligence services; the second a secret message to the Greek Prime Minister urging greater political diversity in his government, which when leaked caused a political crisis in Greece.