Passage: Born into the periphery of the British aristocracy and married to a politician and member of the establishment, she was perfectly placed to meet all the key figures of the Regency and late Napoleonic eras. Recording meetings and conversations often verbatim, she has today become the "Mrs. Arbuthnot" quoted in many biographies and histories of the era. Her observations and memories of life within the British establishment are not confined to individuals but document politics, great events and daily life with an equal attention to detail, providing historians with a clear picture of the events described. Her diaries were themselves finally published in 1950 as The Journal of Mrs Arbuthnot.

Question: What type of establishment are her memories within?
British