Geography has for obvious reasons played a large role in the creation of maritime powers. Easy access to important waterways coupled with equally easy access to necessary natural resources like timber, hemp and tar were essential for establishing the maritime states of early modern Europe. The Baltic Sea region was in a unique position as a launching point for establishing a maritime great power in the early modern period. There were plenty of good, natural harbours to accommodate both trade and warfare. The sea in the Baltic is mostly calm, and the sea lanes served as the most important infrastructure in the region – even if there was a problem with ice during the wintertime. The Pomeranian coniferous forests provided large naturally grown masts and spars. Oak trees grown along the Baltic coast were well suited for the building of wooden warships. The fertile farmland of the southern Baltic in Denmark and the province of Scania (Skåne) provided ample supplies for port cities and maritime communities.

Out of the Viking age and the medieval period gradually emerged two recognizable maritime states, Denmark and Sweden. Denmark was from the beginning a feudal state with a well-defined power base. Once conversion to Christianity had taken place, both Sweden and Denmark engaged in a number of crusades in the Baltic. These crusades were combined maritime operations under direction of the king and his bishops.