Thomas George Churchill Wimsey, 10th Duke of Denver

Thomas George Churchill Wimsey, 10th Duke of Denver was one of the ficitious ancestors Dorothy Sayers and her friends created for her detective Lord Peter Wimsey. A choleric man of the highest social standing (the first Duke of Marlborough was his godfather), he knew "everything about the ancient philosophers except the application of their precepts to himself".

Papers relating to the Family of Wimsey (Christmas 1937) contains several contrived eighteenth-century documents, including a letter from Lord Chesterfield to his son, citing the Duke as an example of "learning without politeness" and the Duke's only son, the then Viscount St. George, as "politeness without learning", which is preferable; both would be better. Most of the booklet deals with the "nine day's wonder" when St. George married his mistress Bessie, on the inadequate grounds that she was pregnant and he loved her.

The Duke refused to see or support his son, especially after the child turned out to be a mere daughter. Eventually St. George fled to Paris, and threw himself on the mercy of his second cousin, Major Richard Wimsey, then in the French army. The booklet also contains letters from the Major's father, who would be heir to the dukedom if St. George died: one urging his son not to do this: if St. George were killed in the wars, "it wd. be the common talk thou wast no better than thy poor Cousin's Murtherer"; another telling how he provided the Duke with the unusual experience of hearing the truth to his face: that the marriage might not be mended and His Grace should make the best of it. There is also a sentimental narrative of the eventual reconciliation, by Horace Walpole.