Book excerpt: A military historian and naval warfare expert delivers a revealing history of the Baltic Sea Campaigns and their significance throughout WWII. From the Battle of Westerplatte on the Polish coast in 1939 to the thousands of German refugees lost at sea in 1945, the Baltic witnessed continuous fighting throughout the Second World War. This chronicle of naval warfare in the region merges such major events as the Siege of Leningrad, the Soviet campaign against Sweden, the three wars in Finland, the Soviet liberation of the Baltic states, the German evacuation of two million people from the East, and the Soviet race westwards in 1945. Naval historian Poul Grooss explains the political and military backgrounds of the war in this theatre while also detailing the ships, radar, artillery, mines and aircraft employed there. He also offers fascinating insights into Swedish cooperation with Nazi Germany, the Germans’ use of the Baltic as a training ground for the Battle of the Atlantic, the secret weapons trials in the remote area of Peenemunde, and the Royal Air Force mining campaign that reduced the threat of German submarine technology. A major contribution to the naval history of this era, Naval War in the Baltic demonstrates the extent to which the Baltic Sea Campaigns shaped the Second World War