General Zod's History
In Krypton's final days, General Zod served as the appointed leader of military defense for the Kryptonian Science Council. Upon learning of the scientific experiments being conducted by Jor-El and his mentor Non, Zod (accompanied by his lieutenant, Ursa) led a raid on Jor-El's laboratory and placed both men under arrest for charges of heresy. The Kryptonian Science Council believed that Jor-El's theories regarding the planet's imminent destruction was causing uncivil panic. Soon after the arrest, Zod learned that Jor-El was actually correct and that the Science Council had lied to him. Ursa and he defected from the council and joined with Non in his quest to warn Krypton's civilian populace of their penultimate fate. Zod and Non grew close, but soon after, the Kryptonian council members apprehended Non and performed a lobotomy on him, turning him into little more than a mindless savage. Zod was incensed. He abandoned all loyalty to the council and swore revenge against them for what they did to Non. Zod tried to enlist the aid of Jor-El in a bid to wrest control from the Science Council, but Jor-El refused, citing that violence was hardly the solution. Zod felt that violence was the only answer at this juncture. Zod, Non and Ursa invaded the Science Council chambers and murdered five council members before they were stopped. Jor-El used the last bit of influence he had with the council to convince them not to execute the three terrorists for treason. The remaining council members placed Jor-El in charge of sentencing the three Kryptonians, and he opted for what he believed to be the most humane solution - exile. Zod felt that Jor-El was a coward for not joining him, and he vowed to avenge himself against the House of El, including Jor-El's heir, Kal-El. Using a special projector, Jor-El transported Zod, Ursa and Non into an interdimensional null reality known as the Phantom Zone. During the years they spent trapped in the Phantom Zone, Krypton exploded, leaving only one presumed survivor - Kal-El.
Zod and Ursa discovered a fragment of an old Kryptonian prison known as Fort Rozz floating inside the Phantom Zone. The prison was transported into the zone due to a projector accident, and for reasons unknown, was able to maintain a corporeal shape. Inside the prison, time passed normally and residents were able to revert back into solid matter so long as they stayed inside the building. Because of this, Zod and Ursa were able to mate and produce a son, Lor-Zod. They raised him inside of Fort Rozz where the child was able to age normally. Zod however, was extremely abusive to the boy and saw him as little more than a tool by which to engineer their final escape from the Phantom Zone.
Years passed, and Zod was able to build small space vessels that could maintain physical form and escape from the Phantom Zone. Lor-Zod was the key to their success, and functioned as a physical tether between the material world and their otherwise ghostly wraith-forms.
Zod knew that the surviving son of his jailer, Jor-El, was living on Earth and Zod wanted to finish off the family line. Further, he decided that Earth was an ideal world ripe for conquering and the establishment of a "new" Krypton. When the time was right, Lor-Zod was launched from the Phantom Zone and sent towards Earth. Upon landing, his ship activated a beacon, which allowed the other displaced Kryptonians the power to free themselves and follow him to Earth.
After reuniting with his son, General Zod led a massive attack against the city of Metropolis and managed to exile Jor-El's son Superman into the Phantom Zone. From there, his followers and he enslaved the city, and began terraforming it with Sunstone structures, similar in design to the buildings of long-dead Krypton. Lor-Zod, having spent some time on Earth with Kal-El, inherited some of Superman's moral fiber and ultimately betrayed his father, attacking him with blasts of heat vision.