Drengs occurred only in South Lancashire, the land between the Ribble and the Mersey. They were free men, lords of small manors, who made customary payments and performed customary services to the king. It is a moot point as to whether they should be classified with the free peasantry; but their duties do resemble those of the free peasantry of circuit 3 and the riding men of circuit 5.
For more detail, see Paul Vinogradoff, English society in the eleventh century: essays in English medieval history (1908); and W.E. Kapelle, The Norman conquest of the north: the region and its transformation, 1000-1135 (1979).