Created by Martin Nodell, Green Lantern first appeared on All-American Comics #16 in 1940, published by All-American Publications, one of three companies that would eventually merge to form DC Comics.

He is among the hordes of superheroes being created, following the huge success of superman.

The publication of this character ceased in 1949 during a general decline in the popularity of superhero comics, but the character saw a limited revival in later decades.

The original Green Lantern in 1940 is called Alan Scott. He is a railroad engineer from New York who, after a railway crash, came into possession of a magic lantern which spoke to him and said it would bring power. From this, he crafted a magic ring which gave him a wide variety of powers. The limitations of the ring were that it had to be "charged" every 24 hours by touching it to the lantern for a time, and that it could not directly affect objects made of wood. Don't ask us why.... beats the hell outta us.

The superhero went on to form the Justice Society of America with several other heroes of that time. But after WWII, the general interest in Superheroes declined and not long after the character resurfaced, he was renamed the "Sentinel", to distinguish him from the more popular modern day Green Lantern.

In 1959, Harold "Hal" Jordan was being introduced as the new Green Lantern in Showcase #22, created by Julius Schwartz. This version of Green Lantern has absolutely no relation to the old one. Hal Jordan was a second-generation test pilot, having followed in the footsteps of his father. He received his ring from a dying alien and was commissioned as an officer of the Green Lantern Corps, an interstellar law enforcement agency overseen by the Guardians of the Universe.

The life of Jordan was rather eventful after gaining the ring to become Green Lantern, one which saw him losing the entire hometown of Coast City, getting possessed by an evil ancient source named Parallax, and merging with Spectre to regain himself.

Guy Gardener first appeared in Green Lantern vol. 2 #59, 1968. He was said to be one of the 2 suitable candidates the lantern detected when the original alien owner died on Earth.

Guy was raised in Baltimore by his parents, Roland and Peggy Gardner. His father, Roland was an abusive alcoholic who beat Guy every day.

When Hal Jordan became the Green Lantern, Guy was made his backup, and the two became close friends.

Gardner became a founding member of the Justice League International after the original JLA disbanded. At a time he even tried to resent Batman's leadership of the group, going so far as to challenge the Dark Knight to a fist fight; Batman immediately downed Guy with one punch.

Guy Gardner's career was an erratic one. Suffering some ups and downs mentally and physically, losing his power ring at one time and renaming himself the Warrior, he eventually returned to the Corps and was being assigned a very major role by the Guardians.

There is a third Green Lantern called John Stewart, first appeared in Green Lantern/Green Arrow #87 volume 2 (1971). The character was created by Dennis O'Neil and Neal Adams.

John Stewart is an architect and veteran U.S. Marine from Detroit, Michigan, who was selected by the Guardians as a backup Green Lantern to then-current Green Lantern Hal Jordan, after the previous backup, Guy Gardner, was seriously injured after getting hit by a car while trying to save a civilian.

As we enter the 1990s, we see more and more new characters created to join the Green Lantern Corps like it is the Mickey Mouse Club.

 

Firstly we have Kyle Rayner in 1994, appearing first time in Green Lantern #48 (volume 3), and created by writer Ron Marz and artist Darryl Banks.

Kyle Rayner was a struggling-but-gifted freelance graphic artist who was raised in North Hollywood and lived and worked in Los Angeles. Kyle was raised by his mother as an only child; his father abandoned his mother when she was pregnant. It was later revealed that his father was a Mexican-American CIA agent named Gabriel Vasquez and that Aaron Rayner was merely an alias.

Rayner joined the superhero group the Titans for a brief time, during which he dated Donna Troy, but eventually became a member of the Justice League (JLA).

At the point of time when Rayner was given the ring, it was supposed to be the last surviving power ring after an event, which was to make Rayner the last Green Lantern.

Well, think again.

Simon Baz is a Lebanese American Muslim from the Detroit suburb of Dearborn, Michigan. He first appeared in The New 52! FCBD #1 (2012) before making his first full appearance in Green Lantern #0.

Baz was caught by the police street racing in a stolen car with an armed bomb in the back of the van. While being questioned by authorities, Sinestro's Green Lantern ring chose Simon as its next ring bearer, recruiting him into the Green Lantern Corps.

After a few turns in his superhero career, he was put under training with Hal Jordan, together with the other newbie Green Lantern of Earth. And after failing that training, Hal Jordan combined the duo's rings into one, which made them only chargeable when the two are together. Supposedly, he hopes that this will make them work better together to defend the planet in his absence.

And the other newbie Green Lantern would be Jessica Cruz. Cruz made her first brief appearance in Green Lantern #20 (2013), before being officially unveiled in Justice League #30 volume 2, 2014.

The coming to power for this new bird was unlike her other comrades, where the ring actually forced itself unto her.

Although being able master the ring's power after some tutorial by Hal Jordan, Cruz was still put into a force partnership with Baz later, and was eventually put under the guardiance of the entire Justice League, during the absence of Hal Jordan from Earth.

If there has to be one more Green Lantern to introduce and talk about, she would be Jennifer-Lynn Hayden (aka Jade), daughter of Alan Scott, created by Roy Thomas and Jerry Ordway.

Jade's first appearance would be in All-Star Squadron #25, 1983. Tracing the timeline, she would be the very first female Green Lantern of Earth.

Due to her father's exposure to magical energies, Jade was born with metahuman powers. Jade's powers first manifested when she was a child when she defended herself against sexual assault. Jade's powers resembled her father's in that she was able to generate green energy and shape it into constructs, and that of her mother's with plant manipulation. Her mother is the supervillian Thorn.

Jade was killed during the Infinite Crisis while defending the universe being destroyed. But like many major superhero characters, the "death" did not last long and she was soon revived.

The Green Lantern Oath

Alan Scott's version:

...and I shall shed my light over dark evil.
For the dark things cannot stand the light,
The light of the Green Lantern!

Hal Jordan's modern day version:

In brightest day, in blackest night,
No evil shall escape my sight.
Let those who worship evil's might,
Beware my power, Green Lantern's light!