North German Federation
The North German Federation (1867–1871) was a short-lived state, established in 1867. First it was a military alliance. Prussia and its allies (15 members: Prussia, Saxony, Hesse, Bremen, Hamburg, Lübeck, etc. ) founded this Federation (or confederation with a constitution) after the Austro-Prussian War of 1866.
During four years its major action existed in legislation unifying Northern Germany. As part of the Austro-Prussian War Prussia had annexed most of its adversaries territories north of the river Main.
In 1871, it was succeeded by the Deutsches Reich (German Empire) founded by the North German Confederation and the south German states of Bavaria, Württemberg, and Baden. The unification of Germany as an integrated nation state officially occurred on 18 January 1871. Bismark (Prussia) was the first chancellor of the German Empire (1871–90).