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 entrance of the canal into the White Sea. There was even a play, a comedy, written about the canal by Nikolay Pogodin. A memory of the canal is also preserved in the Russian language, in the words ""zeka"", ""zek", "z/k"" for "inmate". In Russian, "inmate", "incarcerated" is (), usually abbreviated to "" in paperwork, and pronounced as "" (, "zeh-KA"), which gradually transformed into "" and "", "zek" (both pronounced as ). The word is still in colloquial use. Originally the abbreviation stood for (), literally "incarcerated canal-army-man". The latter term coined in an analogy with the words meaning