Final answer:
The question pertains to the Austro-Prussian War or Seven Weeks' War of 1866, but provided materials mainly discuss the Congress of Vienna and later European stability leading up to WWI.
Step-by-step explanation:
The question refers to the peace treaty with Austria after the Seven Weeks' War in 1866, which is a part of European history. However, the reference materials provided discuss earlier and later periods, particularly around the Congress of Vienna in 1815 and the events leading up to World War I. The Congress of Vienna aimed to restore peace and balance in Europe after the Napoleonic Wars, achieving a long period of relative stability known as the Concert of Europe. This stability was occasionally interrupted by conflicts but served to prevent a major European war until 1914, marking Europe's Long Peace. It is important to note that the peace treaty after the Seven Weeks' War is not covered explicitly in the provided references, as they discuss events both prior and subsequent to that conflict.