There may not be a more important planet in the history of the DC Universe than Krypton. Its explosion, and the one boy who survived & came to Earth, changed the universe in ways no one could have imagined. From donning a blue & red costume to inspiring other heroes like Flash and Batman as well as the Legion of Super-Heroes a thousand years from now. In short, there would be no DC Universe without Superman.

RELATED: Top 10 Alternate Versions Of Superman

Considering how much the DC Universe is indebted to Krypton, very little of the planet's history is unknown. What is known tells the story of a planet filled with turmoil, tragedy, and fear, which are not things one would think of when they think of Superman. What is the history of Krypton, and what do we know about it?

10 The Creation Of Doomsday

Doomsday in the comics

Born from the remnants of the Big Bang some six billion years ago, Krypton was the home of some of the most dangerous creatures in the universe for millions of years. It was for that reason that the alien being known as Bertron chose the planet for his experiment. Looking to create the ultimate life-form, Bertron placed a baby on Krypton and let it be killed. He then took the remains and cloned it, making the next baby invulnerable to what killed the previous one. Bertron did this for decades, speeding up the evolutionary process to create something unstoppable. Bertron's creation would come to be known as Doomsday. Over time, Doomsday killed most of the creatures that lived on Krypton before escaping the planet. Doomsday's actions allowed a weaker race to survive and evolve.

9 The Religion Of Rao

Superman Rao Krypton

Approximately a hundred thousand years ago, an evolved civilization began to grow on Krypton. These people, the Kryptonians, looked up to the sky and saw a red sun that they named Rao and worshipped. The Kryptonians had other gods for a time but became monotheistic under the leadership of Jaf-El.

RELATED: Superman: 10 Ways He Changed In The Golden Age

In the Kryptonian faith, it was believed that anyone born with red hair was blessed by Rao and was given instant acceptance into the Kryptonian military, which was considered to be a great honor. As the Kryptonians further researched science, their belief in Rao waned.

8 The Rise Of Science

Krypton High Council from Smallville

The Kryptonians, finding themselves weaker than many of the horrific creatures that lived on the planet, began to use their minds to overcome the dangers of the world. At an amazing speed, Kryptonians reached scientific achievements well beyond those of other planets. Before long, Krypton was the most advanced society in the universe. This gave the Kryptonians an inflated sense of their greatness, making them feel and act superior to the citizens of other worlds. Not surprisingly, this led to Krypton having icy relationships with other planets in the universe.

7 The Rise Of The Empire

Kryptonians vs Thanagarians

As the most advanced society in the universe, Kryptonians had all but created a utopia. They had cured all diseases, found ways to delay the aging process, and perfected cloning. All Kryptonians had a number of clones made of them to replace any organs or limbs that may become damaged. Kryptonians were essentially immortal.

Krypton looked at the other planets and chose to conquer them to spread the power of the planet. Under the leadership of Admiral Dru-Zod the First, the Kryptonian Empire began to spread across the universe. Even the Green Lantern Corps seemed unable to stop them.

6 The Choice Of Isolation

Cleric watches as Kryptonians die

The expansion of the Kryptonian Empire continued for hundreds of years, spreading the reach of the Kryptonian High Council across light-years. The expansion of the Kryptonian Empire came to a sudden end when Admiral Dru-Zod the First's ship, the Doomsday, was attacked and crashed on Earth, landing in what would one day become Texas.

Not long after that staggering loss, an alien missionary named Cleric came to Krypton and spoke out against cloning. As Cleric gained a following, the Kryptonian Science Council asked Kem-L to create a device that would shut down any insurrections created by Cleric. A xenophobe, Kem-L created Eradicator, a machine that altered all Kryptonian's DNA, making it so they would die if they left the planet. The Kryptonian Galactic Empire soon collapsed and the people of Krypton became isolationists.

5 The 1,000 Year War

World of Krypton 1987 Issue 3

Cleric's message of the evils of cloning continued to spread across Krypton, leading to unrest between those who saw clones as nothing more than spare parts and those who saw clones as sentient beings who deserved to be free. When a woman named Nyra could not find a suitable mate for her son Kan-Z, she woke one of her clones and create a situation where it would meet her son. Kan-Z soon fell in love with the clone and was soon engaged, but when he learned that is fiancee was in fact a clone, he killed her. Kan-Z then murdered his mother for her deception. This incident kicked off a thousand-year war between the two sides of Kryptonian society.

4 The Destroyer

World of Krypton 1987 Issue 3 Black Zero uses the Destroyer

With a planet-wide civil war underway, the scientists of Krypton turned their attention from creating ways to improve life to finding ways to extinguish it. For a thousand years, the pro-clone rights and the anti-clone rights Kryptonians fought a destructive war with nuclear weapons. After a thousand years, the Kryptonian High Council saw that there was no option but to abolish the clone banks and end cloning.

Before the announcement was made, a pro-clone suicide group called Black Zero used the Destroyer, a device that blasted Krypton's core with nuclear energy. Black Zero thought the Destroyer would cause the core to explode, killing everyone on Krypton, but it seemed that all the Destroyer did was cause earthquakes.

3 The Discovery

Superman Jor-El

The thousand-year war left Krypton horribly scarred. What was once a paradise was now a planet of deserts and destroyed landscapes. The Kryptonians themselves had become a cold society, choosing to become sterile and only allow breeding through birthing matrixes.

Although Black Zero's Destroyer didn't work as fast as they thought it would, it did work. While researching a plague that was killing thousands of Kryptonians, Jor-El discovered that Black Zero's device had not failed, but the effects of it were working at a glacial pace. When Jor-El went to the Kryptonian Science Council to tell them of his findings, the Kryptonian ego of the past re-emerged. The Science Council ignored Jor-El's findings.

2 The Last Son

Superman metropolis alex ross

Knowing that his findings were correct, Jor-El began to work on a prototype rocket that would allow Kryptonians to escape the dying planet as well as a way to reverse the DNA shift that Eradicator had done to the Kryptonians centuries before. When it became clear that there was not enough time to build a large ship, Jor-El chose to build one for his unborn son, Kal-El, who was gestating in a birthing matrix.

RELATED: Superman The Animated Series: 10 Behind-The-Scenes Facts Fans Need To Know

Jor-El and his Lara wife set Kal-El's birthing matrix into the rocket and selected a new home for their unborn child; a backward planet called Earth. On this planet, under its yellow sun, the child of Jor-El and Lara would be as powerful as a god, able to rule the people of the world if he so wished. As the rocket left Krypton, the planet exploded.

1 The Doomsday Ship

Lex Luthor controls the Doomsday Ship

The arrival of a flying man in Metropolis enraged Lex Luthor. Before Superman arrived, Lex was the biggest name in the world's greatest city, but now he was being overshadowed by an alien. When Luthor learned that there was a crashed Kryptonian ship under West Texas, he made it his mission to retrieve the ship and use it against the city that had turned its back on him. With the help of Toyman, Metallo, and the Kryptonite Man, Lex was able to locate and fix the Doomsday. As Luthor used the Doomsday to attack Metropolis, Superman arrived and destroyed the ancient ship.

NEXT: DC: Superman's 5 Best Costumes (& 5 Worst)