Between 1400 and 1500 a design revolution in Persia swept away a 2000-year-old tradition of carpet design, replacing abstract geometric patterns with complex floral scrolls dominated by a central medallion derived from the Chinese cloud-collar shape. This revolution represents a major event in world art history, comparable to that which occurred at the same time in Renaissance Italy. It was followed over the next four centuries by a second revolution, during which the principal design elements of the first permeated carpet production at every level throughout Persia and continue to dominate it to this day.