History of the North Sea intense diplomatic crisis. The crisis was defused when Russia was defeated by the Japanese and agreed to pay compensation to the fishermen. During the First World War, Great Britain's Grand Fleet based at Scapa Flow and Germany's Kaiserliche Marine faced each other across the North Sea. Due to its numerical advantage in dreadnoughts, the Grand Fleet obtained Naval superiority and was able to establish a sea blockade of Germany's coast. The goal of the blockade was to deny Germany access to maritime trade including war materials and to guarantee the undisturbed ferrying of British troops. Because of the strong defensive
Baltic Sea British and French fleet attacked the Russian fortresses in the Baltic. They bombarded Sveaborg, which guards Helsinki; and Kronstadt, which guards Saint Petersburg; and they destroyed Bomarsund in the Åland Islands. After the unification of Germany in 1871, the whole southern coast became German. World War I was partly fought in the Baltic Sea. After 1920 Poland was connected to the Baltic Sea by the Polish Corridor and enlarged the port of Gdynia in rivalry with the port of the Free City of Danzig. During World War II, Germany reclaimed all of the southern and much of the eastern shore