The main purpose of the League of Nations, established after World War I in 1920, was to promote peace and prevent conflicts through international cooperation. The League was intended to provide a platform for resolving disputes diplomatically, facilitating negotiations, and enforcing treaties to prevent future wars. It aimed to improve global welfare by addressing issues like disarmament, labor rights, and social justice. Despite these noble goals, the League ultimately struggled with enforcement and lacked participation from major powers, which hindered its effectiveness and contributed to its eventual dissolution after World War II.