The Avengers Initiative, conceptualized as the Protector Initiative and sometimes referred to as Phase 1, was an initiative by S.H.I.E.L.D. operative Nick Fury to form what would become the Avengers. The plan was first conceived in 1995 following Captain Marvel's arrival to Earth.
Over the course of the next seventeen years, Fury would secretly develop the initiative within S.H.I.E.L.D.. The initiative was scrapped by the World Security Council in favor of Phase 2, a weapons development program that sought to harness the Tesseract as an energy source. However, in 2012, the Avengers Initiative was activated following the Chitauri invasion of Earth, with Tony Stark, Steve Rogers, Bruce Banner, Natasha Romanoff, Clint Barton, and Thor coming together to form the Avengers.