Born in 1865, Doeuillet was part of the same generation as Louise Chéruit, Charles Poynter Redfern, and Jacques Doucet. (That is, the second generation - the first generation being born in the early part of the century, like Charles Frederick Worth, John Redfern, and Edouard Doucet.) However, his start came a little later in life. Some sources state that he first worked as a business manager for Callot Soeurs, which opened in 1895. It seems likely that he began working there from the beginning, so one has to wonder - what did he do until then? At thirty, he would not have been starting his career with them. And for them to choose him and keep him on, he must have had experience and talent. Perhaps he had been managing another fashion house before them.
|"Dress by DOEILLET, 18 Place Vendôme, worn by Mlle Adèle Richer", Le Cri de Paris, November 1899|
|In Vanity Fair, 1906 - he doesn't look that handsome to me|
|Dry Goods Economist, 1909 Fall Fashion Number|
|Theatre Magazine, 1911|
|Vogue, April 1922|
There are very few things associated with Doeuillet because of his present obscurity, but one concept I've seen floating around is that he brought out the first robe de style, that it was later called a cocktail dress, and therefore he invented the cocktail dress. Frankly, I cannot tell where this comes from. Searching Google Books is not a precise survey of fashion texts of the time, but when doing it I can only find one reference to Doeuillet in conjunction with the robe de style, and it describes Doucet as the gown's "exponent" and lists several designers making them in 1922.
Part of the trouble is that the term robe de style is not specific. In French, the term was used from the beginning of the century as part of a phrase, comparable to the 18th century robe à la - robe de style Louis XVI, robe de style Empire, etc. I can also find references to robes de style without the reference to an historical time period from an early point: here in 1906 in French, here in 1903 in English. Unfortunately none are pictured, but from the description, it sounds as though the robe de style was mainly in the fabric and trimming, less in the cut: Louis XV bows, an open skirt with a lace tablier, a fichu, and such things.
|From Gazette du Bon Ton, 1915; MFA 2004.25.12|
The term "cocktail dress" does not seem to be extant during this time; "cocktail party" is only attested from 1928, and it makes sense for the dress name to arise after that. As "cocktail dress" first appears in print in the early 1930s (as far as I can tell), it could have been used as a label by Doeuillet-Doucet, but there's no evidence that it was; likewise, there's no evidence that the robe de style was considered a cocktail dress. I have to conclude that this is a myth based on garbled half-truths and leave it there.