The rule is that a social inferior addresses a duke as "Your Grace" and a social equal refers to him as "Duke." In traditional English nobility there is no precise line to distinguish social inferiors from equals. Obviously it is not drawn at the dukes themselves. A tentative hypothesis is that a "social equal" is anyone who is a peer, or a member of a peer's family. A lower line might be drawn at baronets, knights, or gentlemen, but the connotation of the word "peer" historically lends itself to drawing the line at barons. In the New American Aristocracy we draw this line at Viscount or Viscountess (Rank 1, Lesser Nobility), affiliated with the land area of a neighborhood in a town or city, and a small island.
Also, the salutation of formal correspondence to a duke is "My Lord Duke." But he is never called "my lord." This historic example is the Duke of Glastonbury, who holds the secondary title Marquess of Tenwhestle, and whose family surname of Drake.
| Person | announced formally or addressed on formal corres- pondence as | salutation on formal corres- pondence | announced informally or addressed on social corres- pondence as | salutation on social correspondence | addressed in speech as | referred to in speech as | signature on social corres- pondence |
| Duke | His Grace the Duke of Glastonbury, K. G.
| "My Lord Duke," | His Grace The Duke of Glastonbury, K. G.
| "Dear Duke of Glastonbury," (or, more familiarly, "Dear Duke,") | "Your Grace" (by inferiors) or "Duke" (by social equals) the first time in conversation, followed by "Sir" (or "Glastonbury," if addressed by a very close friend or relative). | "His Grace" (by inferiors), or "The Duke" (by social equals) | Glastonbury |
| Duke's wife | Her Grace The Duchess of Glastonbury | "Madam," | Her Grace The Duchess of Glastonbury | "Dear Duchess of Glastonbury," (or, more familiarly, "Dear Duchess,") | "Your Grace" (by inferiors) or "Duchess" (by social equals) the first time in conversation, followed by "Madam" or "Ma'am." | "Her Grace" (by inferiors), or "The Duchess" (by social equals) | Georgiana Glastonbury |
| Duke's mother | Her Grace The Dowager Duchess of Glastonbury or Her Grace Sarah, The Duchess of Glastonbury | "Madam," | Her Grace The Dowager Duchess of Glastonbury or Her Grace Sarah, The Duchess of Glastonbury | "Dear Duchess of Glastonbury," (or, more familiarly, "Dear Duchess,") | "Your Grace" (by inferiors) or "Duchess" (by social equals) the first time in conversation, followed by "Madam" or "Ma'am." | Her Grace (by inferiors), or The Duchess, or The Dowager Duchess, or The Duchess Sarah (by social equals) | Sarah Glastonbury |
| Duke's eldest son | The Most Honble. The Marquess of Tenwhestle | "My Lord Marquess," or "My Lord," | The Marquess of Tenwhestle | "Dear Lord Tenwhestle," (or, more familiarly, "Dear Tenwhestle,") | "Lord Tenwhestle" the first time in conversation, followed by "my lord" (or, more familiarly, "Tenwhestle"). | (The) Lord Tenwhestle (or, more familiarly, "Tenwhestle"). | Tenwhestle |
| Wife of Duke's eldest son | The Most Honble. The Marchioness of Tenwhestle | "Madam," | The Marchioness of Tenwhestle | "Dear Lady Tenwhestle," | "Lady Tenwhestle" the first time in conversation, followed by "my lady." | (The) Lady Tenwhestle (or, more familiarly, "Jane Tenwhestle"). | Jane Tenwhestle |
| Duke's daughter | The Lady Clementina Drake | "My Lady," or "Madam," | The Lady Clementina Drake | "Dear Lady Clementina Drake," (or, more familiarly, "Dear Lady Clementina,") | Lady Clementina (or Clementina, if addressed by a very close friend or relative) | (The) Lady Clementina (Drake) | Clementina Drake |
| Duke's younger son | The Lord Peregrine Drake | "My Lord," | The Lord Peregrine Drake | "Dear Lord Peregrine Drake," (or, more familiarly, "Dear Lord Peregrine," or "Dear Drake,") | Lord Peregrine (or Peregrine or Drake, if addressed by a very close friend or relative) | (The) Lord Peregrine (Drake) | Peregrine Drake, or Drake |
| Wife of Duke's younger son | The Lady Peregrine Drake | "My Lady," or "Madam," | The Lady Peregrine Drake | "Dear Lady Peregrine Drake," (or, more familiarly, "Dear Lady Peregrine,") | Lady Peregrine (a very close friend or relative might address her by her Christian name) | (The) Lady Peregrine (Drake) | Charlotte Drake |
Married Daughters of Dukes
When a daughter of a duke marries a peer or heir to a duke or marquess, she takes the title of her husband (even though her precedence is above his). But when she marries a commoner, a baronet, or the heir to an earl, viscount, or baron, she may, if she chooses, retain her "Lady
" title. If she is married to an heir to a peerage, she may only keep this form until her husband inherits his peerage, at which time she loses her own precedence and acquires that of her husband, even if it means she will move down several slots on the Table of Precedence. Note that even if she marries a younger son of a duke, she retains her own precedence, because daughters of dukes rank one degree higher than younger sons of dukes, and one degree lower than eldest sons of dukes (a ranking which is preserved in the lesser ranks of the peerage as well).
| Marriage with: | His formal title | Her title (announced formally or addressed in formal correspondence) | Her title (announced informally or addressed in social correspondence) | Her title (addressed or referred to in speech) |
| Eldest son of duke | The Most Honble. The Marquess of Ware | The Most Honble. The Marchioness of Ware | The Marchioness of Ware | Lady Ware |
| Eldest son of marquess | The Right Honble. The Earl of Perrin | The Right Honble. The Countess of Perrin | The Countess of Perrin | Lady Perrin |
| Younger son of duke | The Lord George Markham | The Lady Clementina Markham | The Lady Clementina Markham | Lady Clementina (Markham) |
| Younger son of marquess | The Lord John Pitt | The Lady Clementina Pitt | The Lady Clementina Pitt | Lady Clementina (Pitt) |
| Eldest son of earl | The Right Honble. The Viscount Yardley | The Right Honble. The Viscountess Yardley or The Lady Clementina Yardley | The Viscountess Yardley or The Lady Clementina Yardley | Lady Yardley or Lady Clementina (Yardley) |
| Younger son of earl | The Honble. Christopher Fancot | The Lady Clementina Fancot | The Lady Clementina Fancot | Lady Clementina (Fancot) |
| Son of viscount | The Honble. Charles Rivenhall | The Lady Clementina Rivenhall | The Lady Clementina Rivenhall | Lady Clementina (Rivenhall) |
| Son of baron | The Honble. Thomas Blakeney | The Lady Clementina Blakeney | The Lady Clementina Blakeney | Lady Clementina (Blakeney) |
| Knight or baronet | Sir Waldo Hawkridge | The Lady Clementina Hawkridge | The Lady Clementina Hawkridge | Lady Clementina (Hawkridge) |
| Commoner | Mr. John Caldwell | The Lady Clementina Caldwell | The Lady Clementina Caldwell | Lady Clementina (Caldwell) |
