advanced sheep husbandry to Britain and made wool into a national industry. Craven was made accessible by major roads from Ribchester up Ribblesdale and from York through Ilkley. The extent of a Roman villa farm excavated at Gargrave implies it practiced grazing on nearby moorland. By 1000 AD England and Spain were recognized as the pinnacles of European sheep wool production. About 1200 AD scientific treatises on agricultural estate management began to circulate amongst the Cistercian monasteries in the Yorkshire dales. These indicated the way to greatest profit was to produce wool for export. Fountains Abbey strongly affected Craven in upper Wharfedale, Airedale and Littondale. In 1200 the Abbey owned 15,000 sheep in various locations and traded directly with Italian merchants. On the limestone fells it held extensive sheep runs managed by granges located at valley heads to access both the moors and the rough pasture of valley sides. Many granges developed into hamlets. The Fountains' sheep administrative centre was at Outgang Hill, Kilnsey. By 1320 Bolton Priory's flock at Malham was about 2,750 and it built extensive sheep farm buildings there. Accounts show that a quarter of its cheese was sheep's cheese, and that most of the Priory's came from wool sales. It also developed fulling, sorting and grading into industries. Feudal Lords began to imitate monastic management methods for their own estates and in 1350 when the Black Death killed off half the rent-paying farmers they had the bailiffs substitute sheep-pasture for tillage. The export of wool to the Flanders looms, and the concurrent growth of cloth manufacture in England, aided by Edward III's importation of Flemish weavers to teach his people the higher skill of the craft, made demand for all the wool that English flocks could supply. As the profitability of wool further increased some landowners converted all arable land into sheep pasture by evicting whole villages. Over 370 deserted medieval villages have been unearthed in Yorkshire. Henry VIII in 1539 suppressed the Monasteries and sold Littondale and the Bolton Priory's estates in lower Wharefedale and Airedale to Henry Clifford, 1st Earl of Cumberland and Lord of Skipton. By 1600 the wool trade was the primary source of tax revenue for Queen Elizabeth I. Britain's success made it a major influence in the development and spread of sheep husbandry worldwide. In more modern times the Industrial Revolution brought factory production of wool cloth to towns further