After his release from prison, Eisner organized the revolution that overthrew the monarchy in Bavaria ("see German Revolution"). He declared Bavaria to be a free state and republic, the People's State of Bavaria, on 8 November 1918, becoming the first republican premier of Bavaria. On 23 November 1918, he leaked documents from the Bavarian plenipotentiary in Berlin during July and August 1914 that he thought proved that the war was caused by "a small horde of mad Prussian military" men as well as "allied" industrialists, capitalists, politicians, and princes. At the Berne Conference of Socialists held in Berne, Switzerland, he attacked moderate German socialists for their refusal to acknowledge Germany's part in bringing about World War I. For that speech, and for his uncompromising hostility to Prussia, he became bitterly hated by large sections of the German people.