The Austro-Prussian War (German: Preußisch-Österreichischer Krieg) or German War of Brothers (German: Deutscher Bruderkrieg) was fought in 1866 between the Austrian Empire and the Kingdom of Prussia, with each also being aided by various allies within the German Confederation. Prussia had also allied with the Kingdom of Italy, linking this conflict to the Third Independence War of Italian unification. The Austro-Prussian War was part of the wider rivalry between Austria and Prussia, and resulted in Prussian dominance over the German states, having confirmed Prussia's superior military organization and technology compared to Austria at the time.
The major result of the war was a shift in power among the German states away from Austrian and towards Prussian hegemony.