The collection primarily consists of correspondence, including letters both sent and received by Louise Cavendish, Duchess of Devonshire, and members of her family.
There are over 80 letters sent to the Duchess by Spencer Compton Cavendish, 8th Duke of Devonshire (DF14/1/1), as well as over 350 letters and telegrams of condolence sent to her on the 8th Duke's death in 1908 (DF14/1/2). These come from many correspondents, including Winston Churchill, King Edward VII, Queen Alexandra, and Princess Louise, Duchess of Argyll.
There is a group of letters sent to the Duke and Duchess of Manchester by Liberal politician W.E. Forster (DF14/1/3), as well as general correspondence of the Duchess of Manchester (DF14/1/5). The latter includes letters from Queen Victoria; Lord and Lady Derby; Lord Granville; George, Duke of Cambridge; Princess Alice; the Duke of Manchester; Princess Alexandra; Francis Knollys; Princess Mary of Teck; Lord Hartington; and Prince Edward.
Family correspondence includes letters sent by the Duchess to her children Alice Stanley, Mary Montagu and Charles Montagu (DF14/1/4); correspondence of her first husband William Montagu, Duke of Manchester (DF14/1/3 and DF14/1/7); and correspondence of her children, Alice Stanley (DF14/1/6) and Charles Montagu (DF14/1/8).
The majority of the correspondence dates from the time when the Duchess was Duchess of Manchester; the overall covering dates extend to 1922, after the Duchess's death, as the series includes some correspondence of her son, Charles Montagu.
The only other material in the collection aside from correspondence are some papers relating to jewels and jewellery worn by the Duchess when she was Duchess of Devonshire.