From 1972 onwards, until his retirement in 1984, he took extensive manuscript notes of many of the papers passing through his hands. Following his retirement he organised this material geographically and typed out systematic studies of KGB operations in different parts of the world in 10 volumes. He and his family and his archive were exfiltrated from the Soviet Union by the Secret Intelligence Service in 1992. Once in London, Mitrokhin continued to work on transcribing and typing his manuscript notes, producing a further 26 typed volumes, which provided the basis for the two volume book with Professor Christopher Andrew, "The Mitrokhin Archive" (Penguin, 1999). Vasiliy Mitrokhin died in January 2004.
The collection comprises manuscript notes, and the redacted and edited typescript copies of the original notes, of documents from the KGB archive. All documents are in Russian.