Mortimer Gerald Bredon Wimsey, 15th Duke of Denver

Mortimer Gerald Bredon Wimsey, the fictional 15th Duke of Denver (1865-1911) was the son of George Bredon Wimsey, 14th Duke of Denver and Mary Death, his Duchess. He was named after his distant cousin, Lord Mortimer Wimsey, second son of the 11th Duke, the "Hermit of the Wash". Unlike his cousin, he was not of a saintly or intellectual disposition, but one of the hearty, beefy, Wimseys.

He died in a hunting accident in 1911, exposing his family to the death duties recently imposed by David Lloyd George's 1909 budget.

He left two sons: his successor, the 16th Duke, and Lord Peter Wimsey, the detective; and one daughter, Lady Mary Wimsey.

His Duchess, née Honoria Lucasta Delagardie, was the daughter of Francis Delagardie, of Bellingham Hall (or Bellingham Manor), Hampshire.

Literary sources
When the Lord Peter Wimsey series begins (about 1923 when Dorothy L. Sayers published Strong Poison), his father is long dead. Clouds of Witness establishes that his brother is still struggling under financial difficulties, in part brought on by his father's death duties, and in part anticipating his own.

Lord Peter's mother is a strong and sympathetic character, and has attracted much secondary fiction, both by Sayers herself and others. Miss Sayers wrote several pieces of Wimsey fiction, from fragments of chronicles in Old French to the inscription on the 10th Duke's monument. The only piece of this widely published in her lifetime was the "Wimsey Letters" of 1939-40, dealing with their adjustment in wartime, mostly in the voice of the (then) Dowager Duchess.

C. W. Scott-Giles, the herald, worked up Miss Sayers' writings on the Wimseys, including both those privately printed and their own correspondence and discussion on the subject, into the 1977 book listed below.

The Wold Newton connections
The American revisionist, Philip José Farmer, created the Wold Newton family in order to unify the world of pulp fiction; he used both Duchesses of Denver mentioned in this article to link Lord Peter into the mix.

He began by identifying the Death family above with the Claytons, ancestors of Tarzan. He explains the difference of names by one or both chroniclers using pseudonyms; that the Claytons were North Country earls, and the Deaths appear to be Norfolk squires, related to a baronet, is further obfuscation by our sources.

According to Farmer, Mary Death/Joanne Clayton was Tarzan's great-aunt. She herself had three sons:
 * The 15th Duke of Denver, subject of this article.
 * A younger brother, who married an heiress named Collis and changed his name to Wimsey-Collis (or Collis-Wimsey). He later became 1st Earl of Whimsey (sic) and father of the Lady (sic) Barbara Collis, heroine of Edgar Rice Burroughs' Tarzan Triumphant
 * A third brother, whom Farmer further identifies with the celebrated explorer Lord John Roxton, also son of a 14th Duke.

This third brother is actually the oldest of the three, having been born before his mother's marriage, and adopted and legitimated by her husband. Before that he was called John Byron Wentworth, being the result of an affair with Byron's grandson, the twelfth Lord Wentworth; he later returned to that name.

Farmer also finds that the Delagardies descend from the Swedish Count Magnus De La Gardie, of terrible memory. His descendants moved to France, were brought to England by Sir Percy Blakeney, the Scarlet Pimpernel. He declares three Delagardie sisters:
 * Honoria Lucasta, Duchess of Denver, wife of the 15th Duke.
 * Enid Challenger, wife of Professor Challenger.
 * Rhoda Rassendyll, who first married Lord John Wimsey/John Roxton/John Byron Wentworth above, and second Rudolf Rassendyll.

In this reconstruction, Count Magnus is from M. R. James's story of that name; Professor Challenger and Lord John Roxton from Sir Arthur Conan Doyle's The Lost World; Rudolf Rassendyll is the hero of The Prisoner of Zenda and Rupert of Hentzau by Anthony Hope. Byron's actual grandson, Byron Noel King-Noel, was in fact Lord Wentworth from 1860 to 1862, between Lady Byron's death and his own, æ. 26; his father, the Earl of Lovelace, survived until 1893.

NOTE—Some of the material attributed to Farmer in this article was actually researched by other Wold Newton scholars—in particular, Farmer doesn't mention Mary Death at all in the early versions of the family trees, only citing Joane Clayton, and Magnus Delagardie does not appear at all in the original Farmer texts.