These letters from Edward, Viscount Coke to William, Lord Hartington (future 4th Duke of Devonshire) largely relate to the two men's time in the House of Commons, over a few years.
Edward writes regarding: his deep affection for Lord Hartington; differing in public affairs to Lord Hartington; his unswerving support for Lord Hartington and 'our old cause'; woodcock shooting and other game hunting; Lord Hartington's pointers at Newmarket; Harry Fox's election and his hope for Fox's defeat of Sidney; the end of Lord Hartington's courtship for the year; Lord Leicester's trouble quelling rioters concerning his enclosing of a common; plans to visit Lord Hartington; a description of Lord Leicester as his natural father and Harry Pelham as his political father; wishes to Lincoln and Harry Fox; the sudden surrender of the castle of Carlisle; Wade, Duncannon, Grunby and the accounts of the Jacobite rebels' success at Lonsdale; details of a motion from Mr Pitt (rather than Sir John Philips) for an augmentation of naval forces, opposed by Mr Pelham; rebels in Derbyshire and Lord Hartington having to engage his own men; motions in the House of Commons regarding the orders for the cavalry to return and the voting details; the provost of Edinburgh being detained on suspicion of treason; compliments to Jeffs and Duncan.
The final letter in the series is dated a couple of years later and provides Lord Hartington with an account of the events that have recently taken place between him and his wife. He blames his out-of-character behaviour on the madness his wife has caused him and describes his mother-in-law's wish to extract Mary, Lady Coke from Holkham and have her stay in London under her roof, for which she is petitioning the courts. This letter also includes: an account of a visit to Fitzwilliam who had a bad fit; the death of Watkin by horse; his intended visit to Horace Walpole with his mother and father and his pleasure at witnessing Lord Hartington's domestic bliss (CS1/309/5).
It also includes a description [in the hand of Thomas Coke, Lord Leicester] of the circumstances leading up to and the duel between Edward, Viscount Coke and Sir Harry Ballenden (CS1/309/4).