Staples were markets where only certain goods called staple goods were allowed to be sold. The Company of Merchants of the Staple had a monopoly of exporting the staple commodities of England, and certain staple towns (which were constantly changed) were appointed as centres of the trade. The chief export was wool, 'the sovereign treasure' of England, wherewith she was said to keep the whole world warm. In 1328, and again in 1334, all staples were abolished and trade was free according to the great charter. Free trade did not last long, and the staple was fixed at Bruges in 1344. By the Ordinance of Staple 27 Edw. III. (1353) ten staple towns were appointed in England, Wales and Ireland, Westminster and London together being considered as one of the ten. The staple of Bruges was removed from Bruges to Westminster by this Act. In 1360 part of this Act was repealed. Calais[297] remained a staple till it was temporarily suppressed in 1369 (Statute 43 Edw. III., cap. 1). By this Act the staple of wool was in future to be confined to the following English ports: Newcastle, Hull, Boston, Yarmouth, Queenborough, Westminster, Chichester, Winchester, Exeter, and Bristol. The staple towns continued to be changed, and there were great complaints made by the English in Tudor times that the staple was fixed abroad. We read that 'the caryage out of wolle to the stapule ys a grete hurte to the pepul of England, though hyt be profitabul both to the prince and to the merchant also.'[298] The changes in the wool trade in England during the fourteenth, fifteenth and sixteenth centuries caused an industrial revolution, the effects of which are well marked in our literature. The raw material was no longer exported, but in its place the cloth made here was sent to countries which had formerly supplied us with cloth in exchange for our wool. In consequence the number of wealthy merchants increased. With this prosperity the country became proud, and the lawgivers did all they could to foster the manufactures of the country.[299] A Statute passed in 1463 (3 Edw. IV. cap. 4) prohibited by enumeration the import of almost all wrought goods in order that 'the English artificers may have employment.' A similar Act was passed in the reign of Henry VIII., by which foreign books could only be introduced in sheets, so that work should be provided for the English bookbinders. The famous poem written by Adam de Molyneux, Moleyns or Molins, Bishop of Chichester, and Keeper of the Privy Seal (died 1450), which was entitled 'The Libel of English Policy' (1437), contains a full account of commodities exchanged between the countries of Western Europe. The full title of this important _Libellum_ shows its object--'Here beginneth the prologe of the processe of the Libelle of Englyshe Polycye exhorting alle Englande to kepe the see enviroun, and namelye the narowe see, shewynge whate profete commeth thereof, and also worshype and salvacioun to Englande and to alle Englyshe menne.'