The Austro-Prussian War (also called the Seven Weeks War, the Unification War, or the German Civil War, a war fought in 1866 between the Austrian Empire and its German allies on one side and the Kingdom of Prussia with its German allies and Italy on the other, results in Prussian dominance over the German states.

In Germany and Austria it is called the Deutscher Krieg (German war), Österreichisch-preussischer Krieg (Austro-Prussian War) or Bruderkrieg (war of brothers).

In the Italian unification process, this is called the Third Independence War.The major result of the war is a shift in power among the states of the German Confederation away from Austrian and towards Prussian hegemony, and impetus towards the unification of all of the northern German states in a Kleindeutschland that excludes Austria.

The war also strengthens the ideal of the nation state in Italy.

Another result is the severance of the ties of the British royal family, the House of Hanover, with government in Germany after the Kingdom of Hanover is annexed by Prussia as a result of the war (however, the earlier personal union between the two kingdoms had already been dissolved in 1837 because Hanover did not recognize female monarchs (Victoria), and some members of the British royal family will continue to hold German allegiance and titles until the declaration of the First World War).