A number of royal castles, from the 12th century onwards, formed an essential network of royal storehouses in the 13th century for a wide range of goods including food, drink, weapons, armour and raw materials. Castles such as Southampton, Winchester, Bristol and the Tower of London were used to import, store and distribute royal wines. The English royal castles also became used as gaols – the Assize of Clarendon in 1166 insisted that royal sheriffs establish their own gaols and, in the coming years, county gaols were placed in all the shrieval royal castles. Conditions in these gaols were poor and claims of poor treatment and starvation were common; Northampton Castle appears to have seen some of the worst abuses.