History of the North Sea the North Sea though they saw little action. The Austro-Prussian War (1866) resulted in Prussia's gaining full control of the Kiel Canal, allowing their Baltic ports access to the North Sea. France declared war on Prussia 19 July 1870 which initiated the Franco-Prussian War (1870–1871). The French Navy was, at the time far larger and superior to the North German Federal Navy, the Navy of the North German Confederation. Though the French did take a number of merchant ships bound to and from North Germany, shortages of manpower and coal, as well as conflicting orders, made the attempted blockade of
Baltic Sea campaigns (1939–45) had signed the Anglo-German Naval Agreement, which allowed it to expand considerably. The name "Kriegsmarine" was adopted the same year. Though a large, powerful, and professional force, it had to divide its assets between several theaters of war, severely limiting the number and size of the ships it was able to deploy in the Baltic Sea. At the start of the Operation Barbarossa on 21 June 1941 German naval forces in the Baltic Sea consisted of In September 1941 Germany formed the provisional "Baltenflotte", which consisted of the battleship , cruisers , , , and , destroyers , , and