Correspondents include: Ridley Pakenham-Walsh on research concerning John, 1st Duke of Marlborough (9); Keith Feiling on his work proof-reading chapters of "Marlborough" (6); various representatives of George G Harrap and Company, including George Harrap himself (6) on the preparation and correction of proofs; George Trevelyan recommending sources for research (6); Basil Liddell Hart; Maurice Ashley, WSC's researcher (17) and "Sunny" [Charles, 9th Duke of Marlborough] on illustrations for the book (3).Includes copy letters from WSC to the individuals mentioned above and to William, 6th Duke of Portland [earlier William Cavendish-Bentinck].