The Controllers have made several attempts to usurp the Guardians, including the creation of the Darkstars and Effigy. The Controllers are also responsible for the creation of the Sun Eaters, living weapons that, as their name implies, devour stars, leaving the planets orbiting them cold and lifeless.
Approximately 10 billion years before the atomic age of the Earth, an advanced race with vast powers had evolved on planet Oa. Among them was an individual named Krona, who broke certain taboos to probe the origins of the universe and of life itself. In the process, evil was allegedly unleashed on worlds where it had been previously unknown.
To repair the damage Krona had done, his fellow Oans elected to use their immortal lives and powers to combat evil. Krona was rendered helpless and banished from our universe, and the Oans sought effective ways of combating evil. As their numbers were small, no matter how vast their power, they decided to act through agents.
Most of the Oans felt the best method was to work through mortal societies, and thus developed robots known as Manhunters, which were later replaced by living agents called Green Lanterns. These Oans became the Guardians of the Universe and kept their base of operations on Oa.
Another group disagreed, believing that evil was an infection the Oans had let loose, and if it became sufficiently serious, it had to be destroyed. When they failed to convince their fellows of this philosophy, they departed Oa to another dimension. There they developed weapons of awesome power and assigned one to each group. Each member would watch over a specific segment of the multiple universes, and if evil got out of control anywhere, would destroy the affected galaxy. They took the name Controllers.
The Controllers then attempted to create a police force of their own in answer to the Guardians' Green Lantern Corps. Their first creation, the Darkstars, were active for quite some time. Though they never gained as much prominence as the Lantern Corps, after their destruction their numbers swelled. In the end the Darkstars were disbanded. The Controller's then created Effigy, in a second attempt at creating a paramilitary force of their own. Sadly, Effigy (and the Effigy Corps) was unstable, and the Controllers abandoned the pursuit.
Trinity (story arc)
After Krona was freed from the cosmic egg, he wanted to contact the universal consciousness, therefore he sought the aid of the controllers, seeing them as one of the most intelligent beings in the universe. when he arrived at Laboratory World 7431 he demanded their help in return he would give them great power as well. the controllers agreed to help him but eventually they realized how mad krona is, so they betrayed him and attacked him with their technology, however krona proved too powerful for them and he destroyed their entire planet.
The Orange Light of Avarice
Much like the Zamarons, the Controllers decided to follow the Guardians' example and harness a portion of the Emotional Spectrum to power a corp of their own. What portion mattered little to them. All that mattered was that they would be able to control and use it for their purposes. They discovered traces of the Orange Light of Avarice and sought it out. They tracked it to the Vega System in Sector 2828, specifically to a planet called Okaara.
Upon Okaara, they discovered a jungle overrun and being consumed by weeds, which were apparently being driven by the power source they sought. They followed the trail down into an underground palace, where an orange power battery rested. Whatever creature possessed it, the Controllers were certain they were superior and could wrest control over the orange light. They were mistaken. When one Controller attempted to take the battery, the creature known as Larfleeze dispatched his Orange Lanterns and consumed the Controllers with ease. The Controllers who were consumed by the Orange Light have apparently become Larfleeze's Orange Lanterns.
30th Century History
In the latter half of the 30th Century, one Controller decided to use his power to conquer his assigned territory, and unleashed a sun eater,which was his weapon. The Sun Eater menaced Earth and was defeated by the Legion of Super Heroes at the cost of Ferro lad's life. The Legionnaires also confronted the Controller who died of an apparent heart attack that may or may not have been caused by the presence of Ferro Lad's ghost. The Legion was rewarded for their intervention by other Controllers who gave them a "Miracle Machine" that could create matter from thought and that later saved the Earth from invasion before being destroyed by Matter Eater Lad.