- The fragmentation of the Holy Roman Empire, also called the German First Reich, in 1806, after one of the Napoleonic Wars.
- Napoleon reorganised much of the empire into the Confederation of the Rhine, a French satellite, formed by 38 different states.
- On 30 May 1814 the Treaty of Paris declared these German states independent.
- In 1815, the Congress of Vienna redrew the continent's political map and the Confederation of the Rhine changed its name to German Confederation, with the important addition of the two German great powers of Austria and Prussia.
- The failure of the 1848 revolutions.
The creation of the Prussian Zollverein (customs union) in 1818, and its expansion to include other states of the German Confederation, reduced competition between and within states. Railways facilitated business and recreational travel, leading to contact between and among German-speakers from throughout Central Europe. Austria and Bohemia were excluded from this trade union.
- People of the German-speaking areas of the old Empire had a common linguistic, cultural and legal tradition.
- In addition, we should mention, on one hand, their shared experience in the French Revolutionary and Napoleonic Wars, which contributed to reinforce the nationalist sentiment.
- On the other hand, European liberalism offered another intellectual basis for unification.