The League of Nations was formed in 1919 after World War 1 to promote international cooperation and preserve world peace. It was headquartered in Geneva and included Britain, France, Italy, Japan as permanent members along with 58 other nations. The League had goals of preventing future conflicts, disarmament, and improving global issues like health and slavery. However, the League lacked an army and unanimous decision making proved difficult. Major powers like the US did not join, weakening it. The League failed to stop aggression by countries like Germany and Italy in the 1930s, ultimately failing in its primary goal of preventing another world war.