History of Green Lantern(Hal Jordan) 

While testing a flight simulator green light was flying him to a crashed plane. There he found a member of the Green Lantern Corp who had died. The ring chose him to wear the ring and become a Green Lantern. The Guardians of the Universe decided he was worthy enough to become a Green Lantern. Sinestro(who will later become one of Green Lantern's deadly enemies) trains Hal to become a Green Lantern. He has become the greatest Green Lantern and is leading all the Green Lantern Corps.