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!

Green Lantern is the name of several fictional characters, superheroes appearing in comic books published by DC Comics. The first (Alan Scott) was created by writer Bill Finger and artist Martin Nodell in All-American Comics #16 (July 1940).[2]
Each Green Lantern possesses a power ring that gives the user great control over the physical world as long as the wielder has sufficient willpower and strength to wield it. While the ring of the Golden Age Green Lantern (Alan Scott) was magically powered, the rings worn by all subsequent Lanterns were technological creations of the Guardians of the Universe, who granted such rings to worthy candidates. These individuals made up the intergalactic police force known as the Green Lantern Corps.[2]
After World War II, when sales of superhero comic books generally declined, DC ceased publishing new adventures of Alan Scott as the Green Lantern. At the beginning of the Silver Age of Comic Books in the late 1950s, DC editor Julius Schwartz assigned writer John Broome and artist Gil Kane to revive the Green Lantern character, this time as test pilot Hal Jordan, who became a founding member of the Justice League of America. In the early 1970s, writer Denny O'Neil and artist Neal Adams teamed Green Lantern with archer Green Arrow in groundbreaking, socially conscious, and award-winning stories that pitted the sensibilities of the law-and-order-oriented Lantern with the populist Green Arrow. Several cosmically themed series followed, as did occasional different individuals in the role of Earth's Green Lantern. Most prominent of these are John Stewart, Guy Gardner, and Kyle Rayner.
Each of the Earth's Green Lanterns has been a member of either the Justice Society of America or the Justice League of America, and John Stewart was featured as one of the main characters in both the Justice League and the Justice League Unlimited animated series. The Green Lanterns are often depicted as being close friends of the various men who have been the Flash, the most notable friendships having been between Alan Scott and Jay Garrick (the Golden Age Green Lantern and Flash), Hal Jordan and Barry Allen (the Silver Age Green Lantern and Flash), and Kyle Rayner and Wally West (the modern age Green Lantern and Flash), as well as Jordan being friends with West.