After months of fluctuating tensions between Prussia and Austria and several international attempts at negotiation, Austrian troops crossed into Prussia on this day. The ensuing war, which included Prussia's ally Italy, was a disaster for the Austrian Empire. Austria was forced to sign an armistice with Prussia by July 26, 1866, and with Italy two weeks later. Austria gave up valuable territory and heavy indemnities and Prussia was on its way to its eventual forming of the German Empire. (By John Osborne)
Source Citation
"Austria," The American Cyclopedia and Register of Important Events of the Year 1866 (New York: D. Appleton and Company, 1873), 47.