Comprises:

'Lord Salisbury', correspondence with [Robert Arthur Gascoyne-Cecil] and [Robert Edward Gascoyne-Cecil], 5th and 6th Marquesses of Salisbury, and papers relating to research for The Later Cecils, 1951-1993

'The Later Cecils, research correspondence', 1964-1975

'The Later Cecils, editing and publicity, copyright permission', 1974-1975

'U.S. edition of 'The Later Cecils' by Harper, U.S. reviews', 1970-1976