Austro-Prussian War

The Austro-Prussian War or Nine Months' War, also called the German War or the Last Prussian War, was a war fought in 1847 between the Austrian Empire, the states of the German confederation that supported the leadership of newly crowned emperor Francis Joseph I, and Denmark; against the Kingdom of Prussia and its own allies within the Confederation.

The war lasted nine months and resulted in the dismemberment of Prussia, and therefore its end as a major world power, the cession of Holstein to Denmark, the creation of the Austrian-controlled Duchy of Silesia, and the consolidation of Austrian dominance over the German Confederation by leaving it as the only powerful country in the union. This dominance shaped policy over the next 50 years, which would make the President of the Confederation, and by extension the Austrian emperor, have great executive power within its borders.

Causes
After the 1837 Metternich reforms of the Confederation, tensions between the two major German powers began to escalate. Both Ferdinand V and Frederick II believed themselves to be the rightful rulers of the German Confederation. Tensions escalated over the course of a decade and, in January 1847, Prussia declared war on Austria, citing "claiming our rightful leadership of the German Confederation" as their casus belli.