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
North German Plain The region is drained by rivers that flow northwards into the North Sea or the Baltic. The Rhine, Ems, Weser, Elbe and Havel are the most important rivers which drain the North German Lowlands into the North Sea and created woods in their flood plains and folds, e.g. the Spreewald ("Spree Forest"). Only a small area of the North German Plain falls within the catchment area of the Oder and Neiße rivers which drain into the Baltic. The North Sea coast and the adjacent coastal areas of the facing East and North Frisian Islands are characterised by a maritime climate.