Since prehistoric times, the Baltic Sea has functioned as a northern Mare nostrum, connecting the people who live on its shores in ways analogous to the more widely known Mediterranean Sea. Millennia of contacts have crucially shaped the languages, folklore, mythology, religions, technology, and institutions of the people living in this part of the world. The long history of interactions has contributed fundamentally to forming modern ethnic and linguistic identities among Baltic, Finnic, Germanic, Sámi, and Slavic peoples of the North. Understanding any one of these cultures depends on understanding its context in the history of the Circum-Baltic arena.

The present volume is a product of the Austmarr Network. Austmarr, literally ‘East Sea’, is an Old Norse term for the Baltic Sea that reflects the Network's geographical focus on the Baltic Sea Region as an arena of cultural contacts and interaction. The term also relates to the Network's historical emphasis on the period ca. AD 500-1500. At the initiative of Professor Daniel Savborg of the University of Tartu, the Network was initially formed by a small, international group of medieval philologists, folklorists, linguists, archaeologists, and historians, who were united by interests in exploring the role of contacts in shaping cultures, cultural practices, ideologies, and identities through cross-disciplinary dialogue and cooperation. The Network’s growth has been nurtured through annual meetings that move around the Baltic. The founding meeting was held in Tartu, Estonia, in 2011, followed by a symposium in Helsinki, Finland, in 2012; in Härnösand, Sweden, in 2013; in Sundsvall, Sweden, in 2014; in Visby, Gotland, in 2015; and back in to Helsinki for a symposium and workshop in 2016. The largest meeting to date was on returning to Tartu in 2017 with close to 100 participants; the 2018 meeting was held in Stockholm, Sweden; and the 2019 meeting will be in Klaipėda, Lithuania. As the network is an offspring of the Retrospective Methods Network, the work done by participants pays attention to methods and the compatibility of methods across disciplinary frameworks. A central aim of the Network has been to synthesise knowledge about the past produced in different disciplines and national scholarship traditions in order to advance toward truly interdisciplinary reconstructions of human history in the Baltic Sea region.