The Manhunters

History
The Manhunters were the first attempt of the Guardians of the Universe to create an interstellar police force that would combat evil all over the galaxy. Their name and much of their code of behavior was modelled by the Guardians of the Universe on the Manhunters of Ma'aleca'andra (Mars). For thousands of years, they served the Guardians well. However, the Manhunters became obsessed with the act of hunting criminals. Their code, "No Man Escapes The Manhunters", became more important to them than seeing justice done.

Exile
The Manhunters' narrow view on justice lead to their program being compromised. The rogue Oan Krona reprogrammed the Manhunters to prove to the Guardians that there were flaws in an emotionless police force. Krona's reprogramming influenced the Manhunters into deciding that because all crime is the result of emotional responses, and all emotions come from organic life, then the solution on maintaining order in the universe was to remove all organic life from it. The Manhunters descended upon the worlds of Sector 666, slaughtering every organic being they came across into what became known as the Masscre of Sector 666. Only five beings survived the massacre, and they blamed the Guardians for unleashing the Manhunters; these individuals formed an organization known as the Five Inversions and created the Empire of Tears.

The Massacre lead to the Manhunters coming at odds with the Guardians and eventually conspiring to rebel against their masters. The Guardians, however, defeated and destroyed most of the Manhunters. Those that survived hid away on many planets, such as Biot, slowly rebuilding their forces and spreading their "beliefs" to other machines. Since then, the overriding goal of the Manhunters has been to take revenge on the Guardians, as well as on their replacements, the Green Lantern Corps.

The Manhunters infiltrated and liberated many planets disguised as living beings and created a "Cult of the Manhunters" that trained others to be their minions. On Mars, the people of that world started a group of Martian Manhunters based on the lessons of preserving justice taught unto them by the Manhunters and even erected a temple based on the appearance of their inspiration. On Earth, most of the Manhunters' agents were unaware that their masters were robots, or that their real purposes were not noble. Some of these agents became superheroes also known as Manhunters. They wore red-and-blue costumes patterned after the Manhunters themselves. The most famous of these was a big game hunter called Paul Kirk. He was active in the 1940s. He was brought back after he was supposedly killed years before, but was, in truth, placed in suspended animation by a secret conspiracy. He was cloned, and when he finally re-awoke, he dedicated himself to battle those who had used him, eventually dying in the process. However, some of his clones survived.

The Manhunters were discovered by the Justice League who seemingly defeated the Manhunter's leader, the Grandmaster. One of their human pawns, Mark Shaw, adopted a new identity as the costumed hero, the Privateer. However, he was later discovered to be a criminal posing as a hero.

Return of the Manhunters
Years later, it was revealed that the Manhunters not only still existed, but had infiltrated the lives of most superheroes with their agents. They even managed to infiltrate the Olympian Gods, one of their number posing as the goat god Pan. They revealed themselves when a Guardian and a member of the Zamarons tried to evolve some humans into becoming the next Guardians of the Universe, during what became known as the Millennium crisis. In this occasion, there was a massive counterstrike operation by the heroes against the Manhunters, and it seemed that the Grandmaster had finally been destroyed, along with their hidden home planet. Former Privateer Mark Shaw readopted his identity as Manhunter in the wake of the battle, seeking to redeem both the name and himself.

Lost Lanterns
The Manhunters was visited by Hank Hanshaw, the Cyborg Superman, on their planet Biot and welcomed him as their new Grandmaster. Henshaw used his mastery over machinery and Kryptonian technology to upgrade the Manhunters with organic enhancements. They seem to have rebuilt the first Central Power Battery originally destroyed by Hal Jordan (under the influence of Parallax). Biot was also rebuilt using Green Lanterns captured by the Manhunters over the years to power a primitive Green Power Battery. Henshaw decided not to interfere in the reformation of the Green Lantern Corps after an encounter between a Manhunter and Green Lanterns Hal Jordan and John Stewart. However, one of the imprisoned Lanterns, Tomar-Tu, escaped from Biot and crashed on Earth. Investigating, Hal Jordan and Guy Gardner discovered Henshaw's most recent attempts to evolve the Manhunter: the Highmasters, massive Manhunters capable of wiping out entire planets, and powered by imprisoned Green Lanterns. Getting pulled into a Highmaster, Jordan and Arisia used it to destroy the Green Power Battery, incinerating Biot.

Sinestro Corps
The Manhunters have recently resurfaced as part of the Sinestro Corps. They carry miniature yellow Power Batteries inside them which are used by the Sinestro Corps members to charge their yellow power rings. During the Battle of Earth, the Manhunters served as infantry, battling the Justice League, the Justice Society, and the Teen Titans. All Manhunters on Earth went off-line when Henshaw was caught in the Yellow Power Battery's explosion, but a large force of Manhunters off world managed to locate Henshaw's head and restore him to life.