Planet Trade Organization

The Planet Trade Organization is the unofficial name for a galactic-scale empire in the Dragon Ball Universe.

History
The PTO's earliest (indisputably canon) activities were the discovery and conquest of the Saiyan race in Age 730. Frieza employed/enslaved the Saiyan race as soldiers to decimate weak worlds for sale and to conquer strong ones. After seven years (Age 737), Frieza noticed that the Saiyans' average power level was growing to the point where they might be collectively able to threaten him and possibly to give rise to a Super Saiyan. Although the Saiyans learned of this and tried to stop him, they were simply too weak. Frieza destroyed Planet Vegeta and left only four alive: Vegeta, Nappa, Raditz, and (unintentionally) Goku.

In December of Age 762, after Vegeta's failed invasion of Earth to acquire the Dragon Balls, Frieza, having eavesdropped on Vegeta's scouter, traveled to Namek in order to find that planet's set of Dragon Balls. Vegeta followed him there, where he encountered Gohan and Krillin. By that time Frieza had already acquired four Dragon Balls and killed most of Namek's population. Vegeta found all of the Dragon Balls after killing most of Frieza's minions, only for Gohan to steal one. When Frieza summoned the Ginyu Force, Gohan and Krillin were forced to ally with Vegeta. They were not nearly powerful enough to defeat them but were saved by Goku's timely arrival. Captain Ginyu had taken the Dragon Balls to Frieza, who then left to interrogate the remaining Namekians on the password to the Dragon Balls. After a long battle, Ginyu and the Ginyu Force's only other survivor, Jeice, were defeated, but Goku was forced to heal in a regen tank. Frieza returned, having failed to find the password, only to discover that the Earthlings had already discovered it and made two wishes. The Dragon Ball's creator died seconds before Frieza arrived, rendering the Dragon Balls inert. A newly resurrected Piccolo joined the fight against Frieza, but the hour-long battle was in favor of the Changeling before Goku regenerated. After another long battle, Goku hit Frieza with a Spirit Bomb, only for his enemy to survive and murder Krillin. Goku then transformed into a Super Saiyan and defeated Frieza, but not before the tyrant was able to destroy Namek.

In August of Age 764, what little remained of Frieza was rebuilt as a cyborg by his father, King Cold. The two traveled to Earth to search for Goku, but were killed almost upon arrival by Future Trunks.

Later that year, Frieza's older brother Cooler invaded Earth for revenge, but was defeated by Super Saiyan Goku and launched into the sun. Though he did not die, he was unable to lead the PTO, leading to its collapse.

Government
The PTO's government is an absolute monarchy, with Frieza and later Cooler as Emperor. The empire is governed from whichever planet the ruling Changeling inhabits at the time, which was Frieza 79 at the time of the Battle of Namek.

Technology
Work in progress