Austro-Italian ironclad arms race
Austria's defeat in the Seven Weeks War forced Austria to determine a new set of foreign and domestic policies for the future, as Austria's interests since the days of the Holy Roman Empire had primarily been found in Italy and Germany. The Empire thus reformed itself into the Austria-Hungarian Empire following the adoption of the Austro-Hungarian Compromise of 1867 (German: "Ausgleich"), which re-established the sovereignty of the Kingdom of Hungary and placed Hungarians within the Empire on an equal footing with Austrians. Under the "Ausgleich", Emperor Franz Joseph I would be crowned as King of Hungary, while a separate parliament at Pest with powers to enact laws for the lands of the Holy Crown of Hungary would be established.
Hundred Days
At the Congress of Vienna, the Great Powers of Europe (Austria, Great Britain, Prussia and Russia) and their allies , and with the signing of this declaration on 13 March 1815, so began the War of the Seventh Coalition. The hopes of peace that Napoleon had entertained were gone – war was now inevitable.