The earliest industries of Shropshire took their rise from its abundant natural resources; the rivers supplying valuable fisheries; the vast forest areas abundance of timber; while the mineral products of the county had been exploited from remote times. The Domesday Survey mentions salt-works at Ditton Priors, Caynham and Donnington. The lead mines of Shelve and Stiperstones were worked by the Romans, and in 1220 Robert Corbett conferred on Shrewsbury Abbey a tithe of his lead from the mine at Shelve.