all, for only arable land was noted. Ploughing is a minor part of Craven agriculture, and cultivators then had been reduced by the Harrying of the North. Most of Craven is uncultivable moorland and the valley bottoms are usually boggy, shady frost-hollows, with soils of glacial boulder clay very heavy to plough. So ploughing was limited to well-drained moderate slopes. The higher slopes are so full of rock debris that grazing cattle still is the primary living in Craven, with some sheep marginal. Because grazing land was not tallied in the Domesday Book the full areas of the estates of the manors can only be induced The areas of ploughland were counted in carucates and oxgangs: one carrucate being eight oxgangs and one oxgang varying from fifteen to twenty acres. This vagueness comes from an oxgang signifying the land one ox could plough and that varied with the heaviness of the local soil. A carucate was the area that could be managed with team of eight oxen. In 1086 Roger of Poitou was Tenant-in-chief of the western side of Craven: Ribblesdale and the Pendle valley. In 1092 he was granted also Lonsdale to defend Morecambe Bay against Scottish raiding parties. Soon after Henry I of England's succession to the crown in 1100 arose a rebellion of men with a variety of grievances. Several Yorkshire lords were involved and suffered confiscation of their estates. In Craven these were Roger the Poitevin, Erneis of Burun and Gilbert Tison. The King conducted a reorganization of Yorkshire by establishing men more skilled in government. Shortly after 1102 the castleries in Cravenshire were divided between the House of Romille and the House of Percy. The King was clearly intent that Cravenshire should retain a compact structure for he added-in estates from his own demesne. The result was two partially interwoven castleries incorporating nearly all the land in Craven. The Percy estates were mainly concentrated in Ribblesdale with their castle at Gisburn while the Romilles dominated upper Wharfedale and upper Airedale with their fortress at Skipton Castle. 14th century Craven was still suffering from Scottish raiders; for example in 1318 they severely damaged churches as far south as Kildwick. In 1377, in the form of Poll Tax records, the earliest surviving detailed statistics of Craven were collected. From them we can compare the income brackets of various occupations, and the relative worth of villages. The records