Dominium maris baltici
Baltic Sea in 1219
Conquered by Denmark in 1219 (Pomerania conquered in 1219, lost in 1227. Ösel purchased in 1559, lost in 1645)
The establishment of a dominium maris baltici ("Baltic Sea dominion") was one of the primary political aims of the Danish and Swedish kingdoms in the late medieval and early modern eras. Throughout the Northern Wars the Danish and Swedish navies played a secondary role, as the dominium was contested through control of key coasts by land warfare.