To better understand why Marxist Internationalism took on the forms that it did during the revolutionary epoch that followed World War I, it is useful to reconsider the “International Labor and Socialist Conference” that met at Berne from January 26 to February 10,1919. This gathering not only set its mark on the “reconstruction” of the Second International, it also influenced both the formation and the development of the Communist International. It is difficult, however, to comprehend fully what transpired at Berne unless the crucial role taken in the deliberations by Kurt Eisner, on the one hand, and the Zimmerwaldian Opposition, on the other, is recognized. To a much greater extent than has generally been realized, the immediate success and the ultimate failure of the Conference depended on the Bavarian Minister President and the loosely structured opposition group to his Left. Nevertheless every scholarly study of the Conference to date, including Arno Mayer's excellent treatment of the “Stillborn Berne Conference”, tends to underestimate Eisner's impact while largely ignoring the very existence of the Zimmerwaldian Opposition. Yet, if these two elements are neglected it becomes extremely difficult, if not impossible, to fathom the real significance of Berne. Consequently there is a need to reevaluate Eisner's role in the proceedings, particularly his behind the scenes activities, as well as to consider the attempt to resurrect the Zimmer-waldian movement during the Conference. In no small way the responsibility for the fateful decisions taken at Berne, decisions which ultimately proved detrimental to the cause of the International, lies with the hyperactive Kurt Eisner and the relatively passive Zimmer-waldian Opposition.