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
White Sea–Baltic Canal the 1920s had been demoted from a town to a village, now became a town again, and a large port. As is discussed further below, during the 1930s a number of smaller naval vessels were transferred from the Baltic to the White Sea in order to provide warships for the Soviet Northern naval Flotilla, that became the Northern Fleet in 1937. There was no action near the White Sea–Baltic Canal during the Winter War of 1939-1940, as during that war the USSR was invading Finland, rather than the other way around. On the other hand, with Germany's full-scale invasion of