Appendix I: Family Trees


Cavendish and Grey Family Trees


A biography of Henry Cavendish necessarily takes into account his social position. Both of Cavendish’s paternal and maternal grandparents were dukes and duchesses. The family trees in this appendix begin with the grandparents and their siblings, follow with his parents’ generation and then his own, and end with the one after his. By definition he was related to them all, though in most cases the relationship was not close, and he probably met only a small fraction of them, but because in eighteenth-century England, “family pride was such that members were usually well aware of distinguished connections,”1 he would have known about them. Although he associated mainly with persons drawn from another society, one of his own choosing, that of scientific colleagues, he did not abandon the one he was born into, nor could he have. We recognize his aristocratic roots by his style of living, his property, and his will, which left his vast fortune to Cavendishes close to the center of the clan. The dukedom would eventually pass to descendants of his principal heir Lord George Augustus Henry Cavendish, who appears in the last column of the Cavendish family tree. Unless readers of this book are specialists in the history of the period, the names are unfamiliar to them, but they cannot miss the titles that go with them. Dukes, duchesses, and earls are commonplace, as is often great wealth. The family trees reflect the obligation of the head of the family to reproduce himself, taking the form of large families to insure a male heir. They also reflect the fragility of life at the time, even for the most privileged. Five children of the second duke of Devonshire died before their parents. Five children of the first duke, his father, not shown, died before their parents. All five sons of the Duke of Kent died before him, extinguishing the Kent line. Marriages normally, though not always, took place between persons of more or less the same social standing. Not shown on the family charts are illegitimate children, of which the first duke of Devonshire had several, born of unions with an actress and an aspiring actress. The family trees show that many members of the extended Cavendish family did not marry. As a wealthy, single aristocrat, Cavendish was not out of the ordinary. The two family trees in the following pages are nearly complete and, within the limits of their sources, accurate.2 








John Cannon (1984, 28).


The main sources used in developing the family trees are the following. Printed books such as Burke’s, Cokayne’s, and Debrett’s peerages and the Dictionary of National Biography. Online geneological resources such as “The Peerage.” Wills from the main probate court in England, the Prerogative Court of Canterbury. Memorials: for the Cavendish family, a record of dates of death and ages of members of the family interred by custom in All Saints Church in Derby; for the Grey family, photographs taken inside the Grey Mauseleum in Flitton, Bedfordshire. Burke’s Peerage and Baronetage, 106th ed. C. Mosley, 2 vols. (Crans, Switzerland: Burke’s Peerage, 1999). George Edward Cokayne, The Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom: Extant, Extinct, or Dormant, vols. 1–3 (Gloucester: A Sutton, 1982). Debrett’s Peerage and Baronetage (2008). John Charles Cox and William Henry St. John Hope, The Chronicle of Collegiate Church or Free Chapel of All Saints Derby (London, 1881). “The Peerage: A Genealogical Survey of the Peerage of Britain as Well as the Royal Families of Europe,” compiled by D. Lundy ( English Heritage, “The de Grey Mauseleum,” ( The Cavendish and Grey family trees in this book are improvements of those in Jungnickel and McCormmach (1999).