German Empire (1848–1849)
The first iteration of a German Empire or German Realm (German: Deutsches Reich) was as a proto-state which briefly attempted, but ultimately failed, to unify the German states within the German Confederation to create a German nation-state. It was created in the spring of 1848 during the German revolutions by the Frankfurt National Assembly.
Source: Wikipedia — German Empire (1848–1849) (CC BY-SA 4.0)