Demi-monde refers to a group of people who live hedonistic lifestyles, usually in a flagrant and conspicuous manner. The term was commonly used in Europe from the late 19th to the early 20th century, and contemporary use has an anachronistic character. Its connotations of pleasure-seeking often contrasted with wealth and ruling class behavior.
The term was often used as one of disapprobation, the behavior of a person in the demimonde being contrary to more traditional or bourgeois values. Such behaviors often included drinking or drug use, gambling, high spending (particularly in pursuit of fashion, as through clothing as well as servants and houses), and sexual promiscuity. The term demimondaine referred to a woman who embodied these qualities; later it became a euphemism for a courtesan or prostitute.
As the 20th century dawned, changing social mores resulted in the demarginalization of the demimonde. Women's suffrage and the flapper movements resulted in the label demimondaine becoming obsolete. The term commonly used to refer to the class that became 'starving artists'.
Women called demimondaine
Externally, the defining aspects of the demimonde were an extravagant lifestyle of fine food and clothes, often surpassing that of other wealthy women of their day with a steady income of cash and gifts from their various lovers. Internally, their lifestyle was an eclectic mixture of sharp business acumen, social skills, and hedonism. The smart demimondaine, like the fictional Gigi's grandmother, would invest her wealth for the day when her beauty would fade. Others ended up penniless and starving when age took its toll on their beauty unless they managed to marry.
Another famous beauty was Virginia Oldoini, Countess di Castiglione, who came to Paris in the 1850s with very little money of her own and soon became mistress of Napoleon III; after that relationship ended she moved on to other wealthy men in government, finance and European royalty. She was one of the most aristocratic and exclusive of the demimondaines—reputed to have charged a member of the British aristocracy one million francs for 12 hours in her company. She lacked charm, and when her looks went so did her patrons; she died alone and mentally ill years later.
Descriptions of the demimonde can be found in Vanity Fair (1848), a novel which satirizes 19th century society, written by William Makepeace Thackeray. Although it does not mention the terms 'demimonde' and 'demimondaine' (they were coined later), the terms were later used by reviewers and other authors in reference to three characters in it. Lady Crackenbury and Mrs. Washington White are demimonde characters, both of whom Captain Rawdon Crawley lusts after in his younger days. Becky Sharp is perceived as a demimondaine before she presents in court, and then becomes one when she travels through Europe after her husband abandons her.
Possibly the most famous portrayal of the demimonde, albeit from before the word was coined, is in Verdi's opera La traviata (1853). The opera, in turn, was inspired by Alexandre Dumas the younger's La Dame aux Camélias; Marguerite Gautier, the heroine of the book and subsequent play, was based on Marie Duplessis, 1840s Paris courtesan and mistress to a number of prominent men, including Dumas.
In writing his 1924 play Easy Virtue, Noël Coward stated his object was to present a comedy in the structure of a tragedy "to compare the déclassée woman of to-day with the more flamboyant demi-mondaine of the 1890s."
Colette's Gigi (1944) also describes the demimonde and their lifestyle. Gigi is schooled from childhood to be a kept woman, to stifle her feelings in return for a life of ease. "We never marry in our family", says Gigi's mother. But Gigi finds herself a misfit in the demimonde of Paris in the 'Gay Nineties', as she desires true romance with Gaston.
Other uses of the term in fiction
In Henryk Sienkiewicz's Without Dogma (1891), the "demimonde" refers to the affluent, pleasure-seeking portion of society, unbound by morals, religion or tradition, and is loosely analogous to the "Jet Set" of modern times.
In Marcel Proust's Swann's Way (1913), Odette de Crécy is described as a demi-monde. 
Francoise Sagan, in her novel Bonjour Tristesse (1954), uses the term 'demimondaine' to refer to the character Elsa, a young, stunningly attractive woman who leverages her appearance into support by wealthy men, which allows her entrance into the social-world of the upper classes.
The high society men in Peter Matthew Hillsman Taylor's novella The Old Forest (from the story collection of the same name, 1985) use "demimonde" to refer to a group of "adventurous" and intelligent young women in 1937 Memphis, Tennessee; in the story, it is common for the men to continue courting such "demimondames" right up until the time they are married to high society women.
In popular culture
- A chapter in the TV series Penny Dreadful is called "Demi-monde".
- Le Demi-monde, by Alexander Dumas (fils)
- Webber, Carolline (July 19, 2013). "‘My Favors Cost a Great Deal’: ‘The Girl Who Loved Camellias,’ by Julie Kavanagh". The New York Times. Retrieved July 20, 2013.
- Proust, Marcel (1981). Swann's Way. Translated by C.K. Scott Moncrieff and Terence Kilmartin. New York: Random House. ISBN 0394506448.:205
- William Makepeace Thackeray (1848), Vanity Fair.
- Colette (1945), Gigi.
- William Blatchford (editor) (1983), The Memoirs of Cora Pearl: The Erotic Reminiscences of a Flamboyant 19th Century Courtesan. London; New York: Granada. ISBN 0-246-11915-2.
- Katie Hickman (2003), Courtesans : Money, Sex and Fame in the Nineteenth Century . New York: Morrow. ISBN 0-06-620955-2.