The names are sometimes spelled without the letter R, as "incoyables" and "meveilleuses," because these people refused to use the letter in order to show their mourning for the king's execution. (The word for "king," in French, is "le roi.")
After the French Revolution and the Reign of Terror ended, there was a furor for entertainment and pleasure. Stylish women modeled their dress after that of ancient Greece and Rome, wearing semi-transparent tunics in gauze or linen and often displaying cleavage. They also were fond of wigs, often blonde, but also in such colors as black, blue, and green.
Their gentleman companions, the Incroyables, wore eccentric outfits: green jackets, wide trousers, huge neckties, thick glasses, and hats topped by "dog ears", their hair falling on the ears. Their musk-based fragrances gave them the nickname Muscadin. They wore bicorne hats and carried bludgeons, which they referred to as their "executive power."
The leading Incroyable, Paul François Jean Nicolas, vicomte de Barras, hosted luxurious feasts, attended by Royalists, repented Jacobins, and ladies and courtesans alike. Since divorce was now legal under the Directoire, morals tended to be looser than in the past.
Many Incroyables were "nouveau riche," gaining their wealth from selling arms and lending money (usury). When the Directoire period ended, society took a more sober and modest turn.