In his preface, Edwards explains that he originally intended to produce a study of an early modern aristocrat's relationship with his horses, but soon concluded that he could not do so without considering many other facets of William Cavendish's life. The result is a book in which chapters on horses alternate with those devoted to other topics. Readers expecting a systematic discussion of “horses and the aristocratic lifestyle in early modern England” may find this disappointing, but Edwards has assembled a wealth of detailed information about the sources of Cavendish's income and his activities as a major landowner, country magnate, and occasional courtier.

A second son favored by his mother, the notorious Bess of Hardwick, Cavendish quickly acquired a substantial estate in Derbyshire, which he steadily enlarged throughout his life. By the time of his death, he owned 97 manors comprising an estimated 100,000 acres, mainly in Derbyshire, Staffordshire, and Nottinghamshire, as well as £30,000 of stock in the East India Company and other trading ventures, and an interest in coal pits and a lead smelting operation. His wealth contributed to his creation as Earl of Devonshire and appointment as lord lieutenant of the shire, in 1619. Edwards's first chapter examines Cavendish's estate management, providing details about the identity and activity of the stewards who supervised extended blocks of land, and the bailiffs and lesser officers responsible for individual manors. It discusses estate surveys he ordered; the direct farming he carried out on some, but not all, of his demesne lands; and the costs of activities like hedging, ditching, and the care of livestock. This is followed by a chapter on how income was raised from the estate, with sections devoted to livestock husbandry, crop production, and industry. Edwards supplies copious information, much of it summarized in tables, about the purchase and sale of livestock, the grains produced on different manors, and the costs of animal feed and fertilizer.

The third, fourth, and fifth chapters examine how Cavendish bred and raised horses for his own use and for the market. He maintained a stock of brood mares but sometimes purchased stallions, especially prized Spanish Ginetes, for prices as high as £66 13s 4d, compared to the £4–5 normally paid for an average horse. Edwards again supplies detailed information about the breeding of different kinds of horses, the training of foals, the selection and supply of fodder, the design of stables, and the role of farriers in caring for horses and curing their diseases.

Part 2, “Horses and the Aristocratic Lifestyle,” begins with an account of gentry socializing in the provinces, with sections on the occasions for visits, the provision of food for entertainment, and travel by coach or on horseback. This is followed by chapters on the role of Cavendish and other gentry as magistrates and public servants in the country, and on travel to and from London. The latter includes information about the time and expenses incurred in traveling, the facilities used while in transit, the transportation of luggage, and the sending of letters by private carriers and servants before the opening of a public postal service in 1635. A further, particularly rich chapter examines Cavendish's many stays in the capital, initially in rented lodgings but later in houses he purchased in the city, and his acquisition of various luxuries, including paintings, books, spices, and fine textiles. The book concludes with a survey of gentry recreations and pastimes, including the equine activities of hunting, racing, and training horses in the manège, as well as indoor amusements such as music, games, dramatic performances, and reading.

Despite his activities as a horse breeder, Cavendish apparently had limited interest in equine sports, unlike his nephew and namesake, William Cavendish, Earl of Newcastle, whose stable of trained horses acquired a European reputation. Edwards's focus on Devonshire therefore limited his treatment of certain aspects of the role of horsemanship in aristocratic culture. But his meticulous analysis of Devonshire's estate records has yielded a remarkably fine-grained picture of many aspects of the earl's life.