This photo shows an evening dress worn by the English actress Kitty Gordon (1878-1974) in December 1910. It is an exquisite example of the evening wear of the Belle Époque. As the name suggests it's a fashion that took it's form in France, Paris being the fashion capital of the world (as it still is - but back in those days with less competition from other places such as Milan and New York).
The Belle Époque started around 1890-1895 when the bustle disappeared from the female silhouette, and it lasted to the beginning of World War I - an event that was more than just the end of a certain fashion. What marked this fashion from the start was how the skirts fitted very neatly over the woman's hips and thighs, and in the day-wear it became common with leg-of-mutton-sleeves that put further emphasis on the shoulder part of the silhouette and it could even appear on evening-wear. But at the end of the era, like in the photo shown here, it did so less frequently. At the same time there was less emphasis put on the waist and it was usually just marked with a thin sash or belt - as can be seen on this picture.
Other important features of this time in fashion is S-silhouette and the thing they had for laces and sheer materials. The S-shape came from the form of the corset worn to these dresses (they were often long to keep all parts of the body in check - it was after all not just the waist that needed to be thin but also the hips and thighs) and the emphasis at the same time put on the bosom, the ideal woman being slim and voluptuous at the same time. This meant that the dresses were designed to push the decoltage forward and to press the stomach backwards which gave women a look that almost made them resemble ducks (a fact that didn't escape the sketchers of humor and satire at the time).
Both the shape of the dresses and the materials used in creating them made this fashion suitable only for the very rich and idle - more so than many other forms of fashion. Having such a fashion is of course not a new thing, but even so during the 19th century it was possible for the somewhat less well to do to have dresses clearly inspired by the more wealthy classes. It is perhaps no wonder that it is at this time many women turned to a simpler form of fashion, the skirt and blouse, that didn't require a need to be quite as careful and quite as still, that didn't require a corset (or at least one that allowed more movement) and that was cheaper.
But to return to the evening dress shown here, it was of course not a garment meant for everyday use, it was meant to be eye-catching and dazzling and no matter what lay behind it all it is beautiful to look at.