] Apart from the fact that his estate, like that of the Duke of Marlborough, are specifically mentioned, is there any particular reason why you are interested in him?

This is probably not the right place to post this, but the Devonshires, who built Chatsworth, were quite a family in their own right. I just finished reading "Georgiana, Duchess of Devonshire" by Amanda Foreman, a biography of the fifth duchess of Devonshire, who was a scant generation older than JA. It's not quite JA's time or social circle, but I think this book gives fascinating (and IMO, somewhat sad) background information on how the upper classes thought and lived in those days. A bit of gossip: the present Duke of Devonshire came into the title after his older brother, who was married to John F. Kennedy's sister Kathleen, was killed in WWII. The present Duchess, who I understand is largely responsible for Chatsworth's restoration, was the youngest of the "Mitford girls", who often figured in British newspaper headlines in the 1930s.