What was one of the earlier attempts to create an institution to promote international cooperation?

One of the earlier attempts to create an institution for international cooperation was the formation of the League of Nations after World War I, established in 1920. Its primary aim was to prevent future conflicts through collective security and diplomatic dialogue among member states. Although it laid the groundwork for subsequent international organizations, it ultimately struggled to maintain peace and was rendered ineffective in the face of rising tensions leading to World War II. The League's legacy influenced the establishment of the United Nations in 1945, which aimed to promote global cooperation more effectively.