The Baltic Sea is more than an inland sea – it is a historic geopolitical stage. From maritime travel in the Viking era toa NATO-dominated region, this brackish inland sea has been a lifeline for people and countries in northern Europe. The Baltic Sea has served as a hub for economic and political relations – with the dominance of the Hanseatic League in the Middle Ages, the Great Power Battles between Sweden, Poland-Lithuania and Russia, and the dramatic shifts in the aftermath of the Napoleonic Wars as well as two World Wars and the Cold War. But the Baltic Sea is also a place of cooperation. Since the fall of the Soviet Union, the region has been characterized by integration and growth – a development that once again is being challenged by new geopolitical tensions. How will the future be affected by energy flows, climate change and military strategies? In this comprehensive anthology, leading scholars in history, political science, international relations and other subjects are brought together to examine the driving forces that have formed the Baltic Sea region from the 13th century until today.