The letters in the series are largely written by Thomas Coke, Lord Leicester, to the 3rd Duke and Lord Hartington (the future 4th Duke) concerning general elections and Lord Leicester's son, Lord Coke. Lord Leicester writes to the 3rd Duke in a poetic, verbose style even in the briefest letters.
The topics on which he writes to the 3rd Duke include: arrangements for seeing each other; the political opposition, Mr Poole; the influence of John (as Lord Leicester calls the Duke) on his own family especially his brother; playing chess together; a brief mention of visiting Holkham to oversee buildings and plantations; Mr Hayle; choosing able members to serve; Mr Woodhouse; the unfortunate result for [Baldasiar] (the Duke's brother) who was used by Mr Croft and lost the Suffolk election and his pursuit of Mr Croft to Bury; wishes to Mr Gutts & Dun; Lord Coke at Crowleys where he was chosen for Harwich but broke the agreement between Leicester and Mr Pelham; dispute at Harwich; seeing Lord Jack; the grief suffered by him and his wife [on the death of Lord Coke]; Lord Leicester's approval of his nephew who the Duke has written of; his desire for Mr Pelham to choose Lord Leicester's nephew for the Harwich seat.
To Lord Hartington, his tone is more serious and matter-of-fact, he writes of: coming to town to deal with his son, Lord Coke, and his behaviour; the effects of his behaviour on his wife's demeanour and his wish to shield her from their son's most "enormous behaviour" including making an excuse to be in London; Lady Mary [Coke]'s distaste at Lord Coke's proceedings and Lord Leicester's fear that the marriage is irreparable; Lord Coke's dismissal of Lord Leicester's fatherly advice; his hopes for Lord Coke to amend his behaviour; his gratefulness to Lord Hartington in his help with the matter and his good influence on Lord Coke; Sir Everard and the issue of franking [Lord Leicester is Post Master General] concerning Mr Donellan's and Mr Waite's franking and the King's warrant regarding this; 'things in Ireland'; seeing Horace Walpole.