Robe a la Francaise or sack-back robe from the 18th century. Rare surviving gown - Nationalclothing.org
Embroiderers' Guild of Victoria - This robe à la française was made around 1760 using fabric created 10 years before. The sack-back gown - or robe à la française - was a
Sack-Back Gown (robe à la française). While this dress may look like a wedding gown to us, it was not at all customary to marry in white in the 18th century. In
Sack-Back Gown with a Half Skirt (robe à la française). The width of the skirt of this gown indicates it was worn at a formal occasion. The fabric suggests this as well:
Woman's Robe a la Francaise (Sack Gown) LACMA M.60.36.1 (1 of 6) | Fashion, Robe a la francaise, Historical dresses
Dames a la Mode: Sack back, Sacque, Robe a la Francaise- whatever you want to call it!