The U.P.U was founded in Notron City, Notron in 2163.
Although the UPU's intentions were peaceful, around it were other, more belligerent powers. As it expanded through the admittance of more and more worlds, it came into conflict with these powers. In the 27th century, its main adversary was the Jaggaman Empire. However, tensions eased considerably towards the end of the century. In 2684, the hostilities ended, with the Jaggaman Empire disbanding and willing worlds joinging the United Planets.
At the start of the 28th century, the UPU began an unprecedented period of peaceful exploration of the galaxy, free of major conflicts, as its main adversary of the previous century, the Jaggaman Empire, was now a peaceful part of it.
By the 33rd century, the United Planets covered the entire Local Group and parts of the Virgo Cluster
The United Planetary Council was the legislative and executive body of the United Planets. Composed of representatives from the various member planets, the Council held the power to create, amend, and ratify laws. The Council also held a control over the operations of the UPU's military service. The Council also made foreign policy. The Council's meeting chamber was in the center of the Notroni capital city of Notron City, at the center of Notron's one continent
The judiciary was the branch of government responsible for resolving legal disputes. It consists of a hierarchy of courts, with the United Planetary Supreme Court at its apex. Courts usually relied on panels of citizens known as juries.
The Official Currency of the UPU is the Intergalactic Credit. Credits are divided into 20 subcredits.
Admittance into the Federation was either by invitation or successful petition of a world or civilization desirous of joining. In the second case, membership was granted only upon satisfaction of certain requirements. Firstly, the government of the prospective member submitted an official petition to the Federation Council, outlining its desire to join. A lengthy, thorough investigation of the prospective member's culture followed. This investigation could take several years, and was done to ascertain whether or not the culture genuinely shared the values of the Federation: values of benevolence, peaceful co-existence and co-operation, the rule of the law, and equal rights and justice.