The League of Nations, founded in 1920 following the end of World War I, was an international organization designed to promote cooperation and prevent conflict between nations. Synonyms for this term include "International League," "Alliance of Nations," and "Association of States." Other terms that are often used interchangeably with the League of Nations include the "United Nations" and the "World Health Organization." While the League of Nations ultimately failed in its mission to prevent World War II, it paved the way for the development of similar international organizations that continue to work towards peace and cooperation between nations today.