Dorothy L. Sayers: The Lord Peter Wimsey Mysteries

Main Character: Lord Peter Wimsey, aristocrat and amateur sleuth; some of the novels also feature mystery writer Harriet Vane
Setting: England
Bold type indicates a book I've read.

Whose Body? (1923)
Clouds of Witness (1926)
Unnatural Death (1927)
The Unpleasantness at the Bellona Club (1928)
Lord Peter Views the Body (1928) (short stories)
Strong Poison (1930)
Five Red Herrings (1931)
Have His Carcase (1932)
Hangman's Holiday (1933) (12 short stories, 4 including Lord Peter)
Murder Must Advertise (1933)
The Nine Tailors (1934)
Gaudy Night (1935)
Busman's Honeymoon (1937)
In the Teeth of the Evidence (1939) (18 short stories, 4 including Lord Peter)