Side 3

Side 3 is located behind the moon, at L2, and is known as Munzo. Side 3 was the only Side to never use the "open-type" colonies. They instead used "closed-type" colonies, which removed the glass "sky" panels and was a completely "solid" cylinder with no open view to space. This allowed each colony to house greater capacities of people.

In UC 0052, Zeon Zum Deikun moved to Side 3 and began to spread his philosophy of Contolism - essentially that the earth was sacred, and that human beings had a solemn right to protect it. This philosophy also encouraged the people of the space colonies to consider themselves independent from earth. In UC 0058, under the guidance of Zeon Zum Deikun, Side 3 declared independence from the Earth Federation and formed the Republic of Zeon. In UC 0068, Deikun died under mysterious circumstances, and Degwin Zabi took control of the Republic of Zeon.

Under Degwin's leadership, the Republic of Zeon became a dictatorship, and the National Guard regiments Side 3 maintained became a full fledged army. On August 15, UC 0069, Degwin announced the formation of the Principality of Zeon, setting himself up as the ruler and giving his four children unilateral control of the military forces. Simultaneous with this announcement came severe purges of the remaining followers of Zeon Zum Deikun living in Side 3. Between UC 0069 and UC 0078 the Principality of Zeon began mass producing various warships and mobile suits in anticipation of an armed conflict with the Federation.

After the One Year War Side 3 came under the control of Prime Minister Darcia Bakharov, who sued for peace. Bakharov and the Federation reached an agreement whereby the Principality of Zeon would surrender, and Side 3 would be allowed to maintain its independence. The Principality of Zeon was allowed to remain under a party, but was barred from using a Military, under the Treaty of Grenada, but were allowed to construct Mobile Suits for Simulations.