In November 1918 a revolution overthrew the old imperial system in Germany and inaugurated a republic. The revolution was formally completed in August 1919 when the social democrat Friedrich Ebert was sworn in as president. By this time, however, many of the revolution’s original aims and intentions had been swallowed up by new political concerns and lived experiences. For contemporaries the meaning of ‘9 November’ changed, becoming increasingly contested between rival parties, military experts and scholars. This book examines how the debate on the revolution has evolved from August 1919 to the present day. It takes the reader through the ideological battles of the 1920s and 30s into the equally politicised historical writing of the cold war period. It ends with a consideration of the marginalisation of the revolution in academic research since the 1980s, and its revival from 2010.