Mare Balticum, a term coined one thousand years ago by the German chronicler Adam von Bremen, is a sea between central and northern Europe that stretches from latitude 53°N to 66°N and from longitude 10°E to 30°E. Located between Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Poland, Germany, and Denmark, it is linked with the North Sea and the Øresund channel. Although today most commonly known as the Baltic Sea, it is—depending on the viewpoint—also referred to as the East Sea or the West Sea. The definition of the Baltic Sea region is not as clear cut. Its boundaries have been described as “fuzzy, vague and contingent.” Baltoscandia, northeastern Europe, northern Europe, the Baltic World, or the German Ostseeraum appear at first glance to be synonyms, but they carry different ideological connotations and political assumptions of constructed communities. As hinted in Tranströmer's poem, “Östersjöar” (The Baltic Seas), this “European macro region” is multicultural, multilingual, and characterized by a plurality of identities that have intermingled and separated to a higher or lower extent in different eras throughout history. Partly because of these crossroads of several cultures and peoples, the region has attracted—and still attracts—broad scholarly interest, not least in the field of area studies. Several research programs in Baltic studies have been established throughout Europe and beyond, as well as scientific journals to foster research on this territory.

Time and space are the two main categories every historian has to take into account. For a long time, however, historiography has marginalized the spatial dimension of human experience by paying considerably more attention to the different temporalities of historical change. Since the 1990s, this disproportionate emphasis on time over space has been steadily altered, following political geographer Edward Soja's demand “to spatialize the historical narrative” and to open historical science to a geographical imagination including a spatial organization of human society.