Includes: research material for books on the Churchill family, including originals and copies of family correspondence, particularly MS's own correspondence with her mother; personal and office diaries; papers relating to MS's time with her husband in Paris and Rhodesia; correspondence; photographs, both relating to MS's own career, and those which she collected as source material for her books on the Churchill family; speeches; papers relating to visits and lectures undertaken by MS on behalf of the Churchill Centre and International Churchill Society; papers on other Churchill-related organisations with which MS was involved; papers relating to the National Theatre; audio-visual material, including wartime footage of Churchill, documentaries about him, and interviews and events with MS herself; the personal papers of Maryott Whyte, MS's nanny.

This collection has an 'Associated' section, consisting of material from one or more sources distinct from the main series, potentially including material about, but not created, accumulated or owned by, the subject of the collection.