[3] Eisner subsequently proclaimed the People's State of Bavaria but was assassinated by far-right German nationalist Anton Graf von Arco auf Valley in Munich on 21 February 1919.

From 1890 to 1895, he was contributing editor of the Frankfurter Zeitung, during which time he wrote an article attacking Kaiser Wilhelm II, and for which he spent nine months in prison.

He became editor of Vorwärts after the death of Wilhelm Liebknecht in 1900, but in 1905 was called upon to resign by a majority of the editorial board, which favored more orthodox Marxists.

Eisner joined the Independent Social Democratic Party of Germany in 1917, at the height of World War I, and was convicted of treason in 1918 for his role in inciting a strike of munitions workers.

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.

[5] Eisner was assassinated in Munich when German nationalist Anton Graf von Arco auf Valley shot him in the back on 21 February 1919.

[11] His assassination resulted in the elected government of the People's State of Bavaria fleeing Munich and the establishment of the short-lived Bavarian Soviet Republic and parliament.

[18] When the Passau labor union tried to stage a play about Eisner at the bishopric theater in 1920, Reichswehr soldiers and high school students sabotaged it, using weapons from the military arsenal.

Shortly after the National Socialists took power the Monument to the Revolution was destroyed: it was demolished on 22 June 1933, and the urn with Eisner's ashes was moved to the New Jewish Cemetery, where it is still buried.