It has ever been true that, within the rarefied environs of royal courts, how much physical space is taken up by a person is directly in proportion to how important that one is. There have of course been variations on that theme, where relative size varied greatly. But at no time before, or since, has court dress taken up more space, and required more sheer bulk of materials and decoration, than the mid 19th century. Clothing was more densely decorated in the 16th and 17th centuries. Dresses extended out to the sides further in the 18th century. But at no time have skirts gotten bigger around, or trains longer than during this era.
What I have dug up here is a prime example of the extremity that was reached in dimensions. With grateful thanks, of course, to the Metropolitan Museum of New York for this amazing set of garments.
The skirt is four feet in diameter, meaning that the circumference is over 12 feet. The train itself is ten and one half feet long from waist, to end point. And since the dress measures 52 inches from neck to hem, the lady must have been about 5' 3" or 4".
The only other element, apart from the metal embroidery, is a narrow frill of lace along the bodice top. The gold work is nearly neoclassical in design, relying on foliate forms, rectilinear designs, and swags, with a scattering of fleur de lis, marking the still strong connection between Italy, and France. Since the embroidery is entirely of gold, which does not tarnish, it looks spanking new from top to bottom and gleams warmly as light plays over it. Even the gold bullion fringe around the hem of the train is undamaged. Similarly, the silk fabric shows no signs of serious deterioration, or structural stresses. So when not in use, this dress must have been stored flat, otherwise the weight of all the metal decoration would have started to pull the dress to pieces. Its unlikely, though, that this dress saw more than a few uses, so its survival in such condition is less surprising.