Origin

While living on his home world of Korugar, Sinestro was visited by Jewelius Blak, a member of the Green Lantern Corps. Jewelius chose Sinestro has her new apprentice. When Black became incapacitated, Sinestro was contacted by the Guardians of the Universe to become a full time member of the Corps.

Over the years, his sector became known as the most orderly slice of the universe, bringing great renown to Sinestro. After Hal Jordan was accepted into the Corps, Sinestro was asked to help train him, and they became fast friends. But when Hal discovered that Sinestro's peace-keeping methods bordered on fascist, Jordan exposed him to the guardians, and he was thrown out of the Corps and exiled to the Anti-Matter Universe.

The reverse-guardians of the Anti-Matter Universe, the Qward, gave Sinestro a yellow ring with which to terrorize the GLC, thus avenging himself upon them. However, he was thwarted again and again by Jordan and eventually imprisoned in the Central Power Battery on Oa. There he discovered another prisoner of the great lantern: a creature called Parallax, who had been there for millenia. Parallax was a being of pure yellow fear that was responsible for the yellow impurity in GL Rings. Sinestro awoke this creature and helped it possess his nemesis Jordan, faked his own death and in doing so turned Jordan into the renegade he himself once was.

For years, he laid low in the Anti-Matter universe, perpetuating the rumor that he was, in fact, dead. But once the truth about Parallax was discovered by Kyle Rayner, Sinestro returned, battled the newly-freed Jordan and again swore revenge upon his defeat. This time, his revenge is in the form of THE SINESTRO CORPS, an immense army of yellow-ringed fear-mongers who are currently wreaking havoc upon the positive universe and killing dozens of Green Lanterns.

Sinestro's first plan was to find a new host for Parallax. He chose Kyle Rayner and set up a scheme to break his will. First he had Despotellis, the sentient virus, infect Kyle's mother and then he had the crazed villain Alex Nero seemingly replace Kyle Rayner. Sinesto's plan worked, when he captured Kyle and brought him to Qward, he extracted the Ion entity from him and then replaced it with Parallax. Kyle became the new Parallax. Sinestro sent his new Corps to Oa where they killed dozens of Green Lanterns and released many prisoners including Superman Prime and Hank Henshaw, the Cyborg Superman. Sinestro recruited these two into his ranks and they along with Sinestro and Parallax became the heralds for the Sinestro Corps guardian, the Anti-Monitor.

Sinestro went to his home planet of Korugar and defeated that sector's Green Lantern, Soranik Natu. He arrived back on Qward to find Parallax and members of the Sinestro Corps fighting Hal Jordan and other Green Lanterns. The Green Lanterns escaped and managed to save Ion. Sinestro knew it was time for his main attack. He gathered his Corps and went to Earth, the center of the multi-verse. The Sinestro Corps battled the Green Lantern Corps and Earth's heroes in New York while Sinestro led a wave of his troops, including Amon Sur down to Coast City where Hal Jordan and Kyle Rayner, now free from Parallax, engaged them in battle. Sinestro drained the two Green Lanterns powers using Manhunters and Hal countered by doing the exact same thing to Sinestro. The three warriors began a fist fight on the rooftops of Coast City. Sinestro couldn't handle both of them and was arrested. His Corps retreated and he was brought to Oa.

Sinestro revealed that this was all just a plan so that the Green Lanterns would enable lethal force and become feared. Hal didn't believe him but Sinestro claimed victory. Hal regretfully told his old master that he has been put on Death Row.