The League of Nations, created after the First World War, became a new body in the world diplomatic practice, the main goal of which was to prevent the recurrence of a destructive war. Despite the fact that the League of Nations failed to solve many problems, it marked the beginning of international cooperation to eliminate conflicts and establish peace. The authors consider the prerequisites for the creation of the League of Nations and the main directions of its activities. The main achievements and the role of the League of Nations in the further development of international cooperation and the creation of international organizations are analyzed. © 2019 Rossiiskaya Akademiya Nauk, Institut Istorii (Russian Academy of Sciences, Institute of General Hist. All rights reserved.