The hoopskirt first made its appearance in Spanish Court fashion in the 16th century. It was known by several different names in various countries: the krinoline, biedermaier (Germany), caged crinoline, or panier (France), and the trend lasted for nearly three centuries. The French variety, which was called the panier, got its name from the resemblance to chicken baskets at the market.
The ample silk or brocade fabric, which made up the skirt, was supported by a rather elaborate structure underneath. The hoops were made from bone or wood and later replaced by steel and horsehair.
The benefit of a hoopskirt to these ladies was it was lighter in weight and much cooler than the layer of petticoats - sometimes as many as six or seven - to which they were accustomed. The purpose of these underskirts was to provide extra fullness in the skirts of dresses to create the rounded or bell shaped silhouette that was the height of fashion and to make the waist appear cinched in.
Paintings by Velázquez show the extremes to which the ladies of the Spanish Court went. The hoopskirt eventually flattened in front and back and expanded at the sides, giving way to an oval shape, which made it often difficult to pass through doors head on. Ladies often had to literally "sidle" to get through a door.
One can only imagine the difficulties the ladies must have experienced sitting down, not to mention getting dressed in the first place. Given the decline in body hygiene during some of the time the hoopskirt was in fashion, one doesn't want to think too much about what lay beneath the entire outward splendor.
While the hoopskirt craze has diminished, it has not died out completely: hoops and crinolines are still used under wedding gowns and some formal gowns as well as being popular costume accessories for history reenactors.