Green Latern or Hal Jordan was the first Green Lantern of Earth. He is a memeber of the Green Lantern Corps who are an inter-galactic police force. He eventually became its leader after Sinestro killed The Guardians.

When he was a boy his father was killed in plane crash, ironically he was a great pilot. After his death Hal eventually also became a test pilot. One day he was given a Green Latern Ring by a Abin Sur. A dying green latern who crashed on Earth

The ring chose Hal Jordan as its new owner after it scanned for person on Earth with the most will since the rings were powered by emotions and the green stood for will.

He after getting selected by the ring was taken to Oa, the planet of the Green Lanterns to be trained. He was trained by Sinestro and Kilowag

After Sinestro defected and made the Yellow Laterns(opposite of Green Lanterns) he eventually became Corps leader.