Zeon Zum Deikun was a philosopher who developed Contolism: which was both about Ere-ism (that Earth is sacred, and mankind was always meant to leave it and live in space) and Side-ism (all space colonies should be independent from the Earth Federation). He was also the creator of the Newtype theory, which believed that humans, who have needed to communicate with each other throughout time, would eventually develop a sixth sense to mentally communicate.
Since the people of the colonies were so-calledly considered to be on a lower echelon of society compared to those living on Earth, Zeon's teachings were welcomed by the colonies, especially Side 3 (L2), which eventually appointed him leader of the Side. Zeon immediately announced the independence of Side 3, naming it the Republic of Zeon. The Earth Federation responded with the Bardot Policy, which halted all resources to the colony. Deikun responded by creating a colonial guard in case the Federation decided to invade the colony to stop their push for independence.
Soon after, Zeon suddenly died. His friend and closest advisor, Degwin Sodo Zabi, claimed that Zeon named him successor on his deathbed. Many believed that Degwin had Zeon assassinated, but no concrete proof ever surfaced. Degwin changed the Republic of Zeon into the Principality of Zeon, appointing himself as Sovereign and placing his four children in high-ranking roles. Degwin kept the name of Zeon for Side 3 to honor his friend, but mainly to help draw suspicion of Zeon's death away from himself. All of Zeon's most loyal followers were eventually killed in a purge ordered by Degwin.
-The following is taken from Book#3 of the Mobile Suit Gundam novelization by Yoshiyuki Tomino.
The universe is a new environment, which will compel mankind to change. If the first stage in mankind’s evolution was his evolution from an ape to a human, and the second stage was was his breakthrough from feudalism to the rational science of the Renaissance, then the third will be his transformation into a new type of human, a man with profound sensitivity and insight and a far greater awareness of the vastness of time and space.
The transition to Newtypes will be a natural one. The act of walking increased man’s range of movement and helped the concept of tribe and nation-state to develop. Powered vehicles expanded man’s awareness to a global level. And now civilization is advancing into outer space. By living and working in space, man’s consciousness will will transcend the boundaries of Earth and become truly universal. The vastness of space will be “home”. And as man’s consciousness expands, he will begin to tap the unutilized portions of his cerebrum- the over half of his brain cells unused since time immemorial, the enormous untapped mental reserves given by God precisely for the new environment of space- that will act as the trigger.
O people of space! Now is the time to awaken! To realize your latent potential! We are at the dawn of a transformation of mankind. A true enlightenment of the human race. And we may finally be poised, ready to transcend what has always been thought the impossible- infinite space, and time itself. This is no idle dream. To live in a new universe, man must transcend the psychological limitations of his old environment!
It is the height of arrogance for those who remain on Earth to look up at the heavens and believe they can continue to rule over all its inhabitants. It is true that we- the space colonists- were largely shipped from Earth against our will as a population-control measure. But now we are developing a new identity and awareness. We are a new people. We live, eat, and sleep among the stars. We live in infinite space, and we will have access to infinite energy until the sun burns out fifty billion years from now. Our consciousness will expand, and infinite space will be our true home. God has given us the stars to live among.
We are the people of the universe. We have struggled to survive in a harsh environment, and new generations of colonists testify to our success. Now, when we gaze back at Earth, we see a sacred blue and green orb- the cradle of civilization and a sacred home that we must eternally preserve and protect. Our new consciousness as a people of the universe tells us that Earth was not created to be abused and polluted by a few members of an elite, privileged class. Men and women who have never been into outer space still believe Earth belongs to them and still continue rape and plunder it, but their time has passed. Earth must be preserved as the sacred homeland of all mankind. It does not belong solely to an Earthbound elite! By continuing to dream of controlling all of mankind, they forever deny mankind its true destiny.
Autonomy for the Sides, sovereignty for the colonists, does not simply mean a revolt against sovereignty on Earth. It means that every human should move into space, that the government of the Earth and the area around it should be placed in the hands of an alliance of all Sides, and that the Earth itself should be preserved and protected as the sacred birthplace of all mankind. It is easy to expand the numbers of colonies required to accomplish this.
In ancient times the Christians fought bloody battles for control over the birthplace of their religion, but there is no need for humanity to repeat this mistake over Earth.
- In the Mobile Suit Gundam novelization, Deikun's death is attributed to a young Gihren Zabi, instead of Degwin. It is unclear whether or not he was following his father's orders at the time.
- In Mobile Suit Gundam: The Origin, the cause of death, inferred by his aide Jimba Ral, was "myocardial infarction caused by poison formulated from aconite." However, author Yoshikazu Yasuhiko states that Deikun may have died from overwork. It is revealed further in the story that Deikun was extremely exhausted in both body and mind on the eve of his death, based on recollection of his wife Astraia.
- In the original plan, Degwin would have confessed to Artesia that he had indeed orchestrated the murder of Zeon.