In 1870, after France attacked Prussia, Prussia and its new allies in Southern Germany (among them Bavaria) were victorious in the Franco-Prussian War. It created the German Empire in 1871 as a German nation-state, effectively excluding the multi-ethnic Austrian Habsburg monarchy and Liechtenstein. Integrating the Austrians nevertheless remained a strong desire for many people of Germany and Austria, especially among the liberals, the social democrats and also the Catholics who were a minority within the Protestant Germany.
When did France attack Prussia?  Who won the Franco-Prussian War? When was the German Empire founded? What regions was excluded from the German Empire? What was the primary religion of Germany? When was the German empire created? Who was excluded from the German Nation State? What religion was a majority in Germany? What did many people in Germany still want to do?