1. The North German Confederation (1867-1871): This was the first step towards German unification, and it was formed by Otto von Bismarck, the Chancellor of Prussia. The North German Confederation included all of the German states north of the Main River, and it was a military alliance that aimed to protect its members from attack from outside powers.
2. The Franco-Prussian War (1870-1871): This war was a decisive moment in German unification, as it resulted in the defeat of France and the proclamation of the German Empire. The German Empire was a federal state, with each of the German states retaining some degree of autonomy, but with the overall government being controlled by the Prussian-led Reichstag.
3. The First World War (1914-1918): This war was a major setback for German unification, as it resulted in the defeat of the German Empire and the loss of significant territory. The German Empire was replaced by the Weimar Republic, which was a democratic state, but it was also plagued by political instability and economic problems.
4. The Second World War (1939-1945): This war was an even greater disaster for German unification, as it resulted in the complete destruction of Germany and the division of the country into two separate states: East Germany and West Germany. East Germany was a communist state, while West Germany was a democratic state.
German unification was finally achieved in 1990, with the reunification of East Germany and West Germany. The reunification was a major milestone in European history, as it marked the end of the Cold War and the beginning of a new era of peace and cooperation in Europe.