Louise-Renée de Kéroualle
by Pierre Mignard, 1682

National Portrait Gallery, London

head shoulder lower sleeve bodice

Louise-Renée Kéroualle:
Duchess of Portsmouth, Countess of Fareham, Baroness Petersfield, Duchesse d'Aubigny
Mistress of Charles II, King of England (yes, the son of the one who ended up shorter than he started out...), and mother of one of his many bastards (as far as anyone can tell), got the above titles en lieu of her son because Louis XIV wanted to prevent Charles II from inheriting them along with the fief of Aubigny.
There is hardly any footage of her style of dress, obviously a kind of deshabillée. It can be seen in French and English portraits of the 1670s and early 80s, with or without a waist seam, and clearly not modeled to hug the figure. The chemise invatiably shows between 3-4 jewelled clasps closing the centre front; the sleeves are full, half open and held by a jewelled band.

Pierre Mignard aka Mignard le Romain:
* 17/11/1612 Troyes
+ 30/5/1695 Paris
Favoured by Louis XIV - he painted such celebrities as the royal mistresses, la Montespan, la Sévigné and la "Maintenant" - but refused to join the Académie Royale for reasons of rivalry with its head. Also did religious paintings, but is most noted for his portraits of the nobility.