The Avengers are Earth's foremost major organization of costumed superhuman crimefighters, adventurers and heroes dedicated to safeguarding the world from any threat beyond the power of conventional peacekeeping forces or any which any of them can't handle alone.
Founded several months after the incorporation of the hero team Fantastic Four, the Avengers became the first superhuman team to be granted full official government sanctions by the National Security Council of the United States, the General Assembly of the United Nations, and later by the international intelligence/law enforcement agency S.H.I.E.L.D.. The Avengers were created by Stan Lee and Jack Kirby, first appearing in Avengers #1. (1963)
Their success has resulted in various splinter-teams and spin-off teams, both nationwide and worldwide, and with different members.