A cabriole leg is one of (usually) four vertical supports of a piece of furniture shaped in two curves; the upper arc is convex, while lower is concave; the upper curve always bows outward, while the lower curve bows inward; with the axes of the two curves in the same plane. This design was used by the ancient Chinese and Greeks, but emerged in Europe in the very early 18th century, when it was incorporated into the more curvilinear styles produced in France, England and Holland.