Oan Citadel
General Information
Official name: Oan Citadel
Created by: John Broome
Gil Kane
Sector: Space Sector 0000
Planet: Oa
Residents: Guardians of the Universe
Green Lantern Corps



The Citadel of Oa is located on the planet Oa, and is the headquarters and meeting hall of the Guardians of the Universe. Millennia ago, the Guardians used the citadel laboratories to create a robotic army of soldiers to safeguard the universe. These beings became known as the Manhunters, but they later rebelled and left Oa permanently, taking up new refuge on the planet known as Biot. Centuries later, the Guardians established a new peacekeeping task force known as the Green Lantern Corps. The citadel became a training center and proving ground for the Corps. Members of the Green Lantern Honor Guard such as Kilowog and Tomar-Re recruited fresh warriors to train and serve in the Corps. The citadel houses the Central Power Battery of Oa - a reservoir of energy which embodies raw willpower. It is also where the mysterious Book of Oa is kept, specifically in one of the Guardian's main stronghold rooms known as the Hall of Great Service. The Guardians select chosen Green Lanterns to serve as Keepers of the book. In the first wave of the Green Lantern Corps, the Keeper of the Book of Oa was Tomar-Re. With the rebirth of the Corps, the position was handed to the ever-stern Slyggian, Salaak. The Oan Citadel also houses hundreds upon hundreds of Sciencells - spherical containment capsules where the worst intergalactic villains of the universe are imprisoned.

Destroy and Rebuild

The Oan Citadel has been destroyed and rebuilt numerous times. It was first destroyed during the Crisis on Infinite Earths in an attack which resulted in the deaths of several guardians. It was rebuilt shortly thereafter, but abandoned when the Guardians sent themselves into exile to be with their feminine counterparts the Zamarons. The Citadel was destroyed again years later when Hal Jordan, infected by the entity of fear known as Parallax,fought with Kyle Rayner over Oa and destroyed the planet. Hal's friend, Tom Kalmaklu rebuilt the Citadel and the rest of the planet with Hal's old ring. When the Green Lantern known as Kyle Rayner possessed the power of Ion, he resurrected the Guardians and they established a new Green Lantern Corps, as well as a new, larger citadel and several sector houses.


The Citadel since then has come under attack several times by various groups, such as the Spider Guild of the Vega System, the Sinestro Corps, and the Black Lantern Corps, each time surviving, though the Guardians were kidnapped during the latest assault on Oa.

Points of Interest


  • The Oan Citadel is not to be confused with Green Lantern Citadel, which was an Earth-based construct developed by a small team of seven Green Lanterns. This citadel served as the headquarters for the Earth-based Corps, as well as a safe house for the New Guardians.


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