Paper made of cotton and other vegetable fibres by the Chinese was obtained by the Arabs in trade, through Samarcand. When they captured that city, in 704 A.D. they learned the process from Chinese captives there, and soon spread it over their empire. It was known as "Charta Damascena" in the Middle Ages, and was extensively made also in Northern Africa. The first paper made in Europe was manufactured by the Moors in Spain, at Valencia, Toledo, and Xativa. At the decline of Moorish power, the Christians took it up, but their work was not so good. It was introduced into Italy through the Arabs in Sicily; and the Laws of Alphonso, 1263, refer to it as "cloth parchment." The earliest documents on this thick "cotton" paper date from the twelfth and thirteenth centuries, as a deed of King Roger of Sicily, dated 1102, shows. When made further north, other materials, such as rags and flax, were used. The first mention of rag paper, in a tract of Peter, Abbott of Cluny from 1122 to 1150, probably means woolen. Linen paper was not made until in the fourteenth century. The Oriental papers had no water mark,--which is really a wire mark. Water-mark paper originated in the early fourteenth century, when paper-making became an European industry; and a considerable international trade can be traced by means of the water marks. The French Encyclopædia corroborates Blanchet's statement that the common notion that the Arabic and early European papers were made of cotton is a mistake; the microscope shows rag and flax fibres in the earliest. Frederic Aumonier says: "From the earliest times man has longed to conceal the baldness of mud walls, canvas tents or more substantial dwellings, by something of a decorative character. Skins of animals, the trophies of the chase, were probably used by our remote ancestors for ages before wall-paintings and sculptures were thought of. The extreme antiquity of both of these latter methods of wall decoration has recently received abundant confirmation from the valuable work done by the Egyptian Research Department, at Hierakonopolis, where wall-paintings have been discovered in an ancient tomb, the date of which has not yet been determined, but which is probably less than seven thousand years old; and by the discovery of ancient buildings under the scorching sand dunes of the great Sahara, far away from the present boundary line of habitable and cultivated land. The painted decorations on the walls of some of the rooms in these old-world dwellings have been preserved by the dry sand, and remain almost as fresh as they were on the day they left the hand of the artist, whose bones have long since been resolved into their native dust." From the Encyclopædia Britannica I condense the long article on "Mural Decoration": There is scarcely one of the numerous branches of decorative art which has not at some time or other been applied to the ornamentation of wall-surfaces.