A number of royal castles were linked to forests and other key resources. Royal forests in the early medieval period were subject to special royal jurisdiction; forest law was, as historian Robert Huscroft describes it, "harsh and arbitrary, a matter purely for the King's will" and forests were expected to supply the king with hunting grounds, raw materials, goods and money. Forests were typically tied to castles, both to assist with the enforcement of the law and to store the goods being extracted from the local economy: Peveril Castle was linked to the Peak Forest and the local lead mining there; St Briavels was tied to the Forest of Dean; and Knaresborough, Rockingham and Pickering to their eponymous forests respectively. In the south-west, where the Crown oversaw the lead mining industry, castles such as Restormel played an important role running the local stannery courts.