The saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not known precisely when riders first began to use some sort of padding or protection, but a blanket attached by some form of surcingle or girth was probably the first "saddle", followed later by more elaborate padded designs. The solid saddle tree was a later invention, and though early stirrup designs predated the invention of the solid tree, the paired stirrup, which attached to the tree, was the last element of the saddle to reach the basic form that is still used today. Today, modern saddles come 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. The saddle was a crucial step in the increased use of domesticated animals, during the Classical Era. Etymology The word "saddle" originates from the Proto-Germanic language , with cognates in various other Indo-European languages, including the Latin sella. Parts Tree: the base on which the rest of the saddle is built – usually based on wood (or on a similar synthetic material). The eventually covers it with leather or with a leather-like synthetic. The tree's size determines its fit on the horse's back, as well as the size of the seat for the rider. The tree provides a bearing surface to protect the horse from the weight of the rider. The solid saddle-tree raises the rider above the horse's back, and distributes the rider's weight, reducing the pounds per square inch carried on any one part of the horse's back, thus greatly increasing the comfort of the horse and prolonging its useful life. Seat: the part of the saddle where the rider sits. It is usually lower than the pommel and cantle - to provide security. Pommel (English)/ swells (Western): the front, slightly raised area of the saddle. : the rear of the saddle Stirrup: part of the saddle in which the rider's feet are placed; provides support and leverage to the rider. Leathers and flaps (English), or fenders (Western): The leather straps connecting the stirrups to the saddle tree and leather flaps giving support