A sadle is a supportive structure for a rider or other load, fastened to an animal's back. The most common type is the equestrian saddle designed for a horse, but specialized saddles have been created for camels and other creatures. The earliest saddles were simple pads attached with a surcingle seen by 800 BC, with the saddle tree coming into use circa 200 BC, and paired stirrups by 322 A.D. Saddles in the styles seen today date back to the 18th and 19th centuries. Today, modern saddle comes in a wide variety of styles, each designed for a specific equestrianism discipline, and require careful fit to both the rider and the horse. Proper saddle care can extend the useful life of a saddle, often for decades.