1815 Congress of Vienna ends the Napoleonic Wars and establishes the borders for Prussia, Russia, and Austria. These states would enter into the short-lived Holy Alliance, but the steady peace would break apart with rising nationalism.
"Congress Poland" would be established by Vienna, until an increasingly powerful Russian Tsar absorbs it in 1867.
With the the liberal rebellions of 1848, a collection of German states and radicals meet in Frankfurt to discuss the possibility of unification. Talks fall through after both Prussia and Austria decline.
The Hungarian Rebellion of 1848-1849 was spurred by liberal agitation but became increasingly nationalistic. Although in Austrian territory, Franz Joseph would call upon Russian troops to put it down under the Holy Alliance.
In 1854 a political crisis over who is the protector of Christendom in the East. Widely considered to be the first modern war, it would end with The Franco-Turkish-British alliance victorious over an embarrassed Russia.
In 1867 a defeated Austria will bitterly accept a larger role for the Hunagrains in their state. An Austrian Emperor and a Hungarian King would survive until 1918.
In 1872, Prussia would declare itself the true state of the German Empire after destroying France. With this, a new balance of power in Europe would be established until World War 1.