Bavaria , WÃ 1\/4 rttemberg , and Baden ( together with parts of the Grand Duchy of Hesse which had not originally joined the federation ) , joined with the Federation to form the German Empire . William I became German Emperor he was not called the Emperor of Germany because it was thought that title could only be used if Austria was included . Following the Confederation 's quick , decisive victory over the Second French Empire and the subsequently formed Third Republic in the Franco-Prussian War of 1871 , Bavaria , WÃ 1\/4 rttemberg , and Baden ( together with parts of the Grand Duchy of Hesse which had not originally joined the confederation ) , unified with the states of the Confederation to form the German Empire , with William I taking the new title of German Emperor ( rather than Emperor of Germany as Austria was not included ) .