Constitution of the German Confederation (1871) in the context of "Unification of Germany"

The Unification of Germany (German: Deutsche Einigung, pronounced [ˈdɔʏtʃə ˈʔaɪnɪɡʊŋ] ) was a process of building the first nation-state for Germans with federal features based on the concept of Lesser Germany (one without the Habsburgs' multi-ethnic Austria or its German-speaking part). After the deletion of the German Confederation due to the Austro-Prussian War, it commenced on 18 August 1866 with the adoption of the North German Confederation Treaty establishing the North German Confederation, initially a military alliance de facto dominated by the Kingdom of Prussia which was subsequently deepened through adoption of the North German Constitution.

The process symbolically concluded when most of the south German states joined the North German Confederation with the ceremonial proclamation of the German Empire (German Reich) having 25 member states and led by the Kingdom of Prussia of Hohenzollerns on 18 January 1871; the event was typically celebrated as the date of the German Empire's foundation, although the legally meaningful events relevant to the completion of unification occurred on 1 January 1871 (accession of South German states and constitutional adoption of the name "German Empire"), 4 May 1871 (entry into force of the permanent Constitution of the German Empire) and 10 May 1871 (Treaty of Frankfurt and recognition of the Empire by the French Third Republic).