This paper explores trade connections - or the lack of such - between copperworks and copper processing plants in the Oldenburg Monarchy in the eighteenth century. Domestic customs areas, high tariffs on raw material export and import bans sought to encourage domestic copper and brass goods production of Norwegian copper raw material, however this was only realised halfway. The raw material from Norway was largely exported, and copper and brass materials used to produce copper-, brass and bronze goods were imported from all over the world. The copperworks and processing plants in the Monarchy never became strongly integrated due to several reasons. First, shareholders of copperworks acquired favourable credit deals abroad, and preferred to export the copper, and second, copper materials had different features and processing plants used all sorts of copper inputs in the making of goods, not only copper raw material. Norway produced mostly gar copper, so copper plants and coppersmiths had to turn elsewhere for other types of copper. Production of copper and brass goods increased, but did not meet the domestic demand partly due to a strong foreign competition. The optimal goal of 'mercantilist theory' regarding copper and brass import substitution was not reached.
