In this series of letters William Kent writes largely to Lady Burlington, but also to Lord Burlington and the 3rd Duke of Devonshire. He writes about the news of the day (including his worried reaction to the Jacobite uprising), his contacts and activities and includes regular reference to their mutual friend Ferdinando Fairfax and his brother Brian.
The letters written to Lord Burlington concern: their mutual acquaintances; work they are doing on various buildings; the Jacobite rebellion and Kent's concern about it; instructions for works that need doing.
In his letters to Dorothy Boyle (née Savile) Lady Burlington, he writes concerning: the health of the family; their mutual acquaintences; news received; his travel plans; his thoughts about the Jacobite rebellion and descriptions of social gatherings.
He often writes quite colloquial phrases in the letters to Lady Burlington such as "my service to him" (meaning Lord Burlington) and he uses the family nicknames (Cha, Jewel, Nando etc) highlighting the familiarity he had with both Lord and Lady Burlington.
In the letter to the Duke of Devonshire Kent writes concerning the progress of the building of the house [Devonshire House] including the level of the brick work and the cost for the next part of masonry and carpentry, as well as his estimation that the whole house will be covered by the time Lord Devonshire returns to London (CS1/206/1A).
There is also included in this series a receipt for £1000 from the 3rd Duke of Devonshire, May 1740.