The importance of fish for the medieval and early modern economy in the Baltic Sea is known through separate studies by historians and archaeologists. This article aims to combine zooarchaeological data with account books from castles in Kastelholm (Åland Islands) and Raseborg (south-western coast of Finland) in order to understand the processing and transport of fish in the area. Fish was paid as tax by the peasants but was also fished by the castle fishermen and brought to the castles to be consumed there. Here, the preserved fish products are primarily studied through pike and cod, which represent the main economically important larger fish species in the Baltic Sea. The study reveals some differences between the castles studied and the importance of fish for the castle economy.
