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 nineteenth to the early twentieth century, and contemporary use has an anachronistic character. Its connotations of pleasure-seeking often contrasted with wealth and ruling class behavior.
The term 'demi-monde' is French for "half-world". It derives from a comedy called Le Demi-Monde, by Alexandre Dumas, fils, published in 1855.
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 twentieth 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'.
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. Intelligent demimondaines, like the fictional Gigi's grandmother, would invest their wealth for the day when their beauty faded. Others ended up penniless and starving when age took its toll on their beauty, unless they managed to marry.
A 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.