World Government

The World Government from One Piece may seem to care about the welfare of people, but the majority are power hungry and corrupt. They use the navy to hunt down pirates and anyone who disobey them. They ally with 170 counties and run the marines they use to commit questionable actions such as killing people who they think are too powerful to control. They believe that they're word is final, true, and ultimately just. Those who oppose are villains and enemies of the world itself. Within the World Government are some honest good men with good intentions, however they are heavily outnumbered by the more corrupt and power hungry individuals.

Centuries Ago
About one millennium ago, the World Government appeared after the Void Century. As it appeared, it managed to get many powerful families and countries to join them. Over time, the World Government manage to gain the support of 170 countries.

The Pirate King's Execution
Pirate King, Gol D. Roger turned himself in after finding the One Piece and living his dreams. Before the execution, Roger told Monkey D. Garp to watch after his son, Ace, which the latter reluctantly agreed to. After Gol D. Roger's execution, a pirate era emerged much to the World Government's disdain.

Ohara Incident
The Gorosei was cracking down on the archeologists on the island of Ohara because they realized that the archeologists found out about the World Government's past. The Gorosei sent Spandine there to investigate he situation. After discovering Nico Olvia (an infamous archeologist), Spandine ordered a Buster Call on the small island. Fortunately, Nico Robin escaped from the incident alive but because of her ties to her mother, Nico Olvia, and knowing a bit about the past of the World Government, she was branded the name "Devil Child" and labeled an international criminal.

Water 7 Saga
Nico Robin turned herself in to the Government agents, CP9 for her involvement in the Ohara Incident. CP9 also captured Franky because Spandam wanted him to hand over the Blue Prints to the ancient weapon, Pluton. But with the efforts of the Straw Hats, the Franky Family, and a few others Nico Robin and Franky were saved.

Summit War Saga
Whitebeard wages war against the Marines, so that he can rescue his adopted son Portgas D. Ace from execution. Because of Ace's blood relation to the Pirate King, the World Government wanted the execution of the latter which they suceeded in. Before Whitebeard's died to the injuries inflicted by the Blackbeard Pirates, he announced to the World that there is a One Piece out there.

Time Skip
Because of Whitebeard's announcement to the world that there is a One Piece out there, many people became pirates and sought out to find the One Piece. Around the same time, Sengoku stepped down from the role of the Fleet Admiral and Akainu became his successor. Because Akainu is the Fleet Admiral, he now seeks out more justice in the name of the World Government.

Role
The World Government plays many roles in the One Piece world. The leaders of the World Government, the Gorosei have absolute say over everything in the One Piece world. It run the Marines, Cipher Pol Agency, and have the allegiance of about 170 nations and many powerful families such as the Donquixote Family. The World Government also appoints the Shichibukai (pirates who works for the World Government) so that they can be used to enforce the power of the World Government. With that, the World Government tracks down anyone who opposes it by having them captured or having bounties placed upon them.

There are also important locations that the World Government has special control over like Enies Lobby: a place where criminals are judged, Impel Down: the great underground prison, and Marineford: the head of the navy. But the World Government's main headquarters is in the Holy Land, Mariejois, that is located on the Red Line.

The World government also places a lot of power in the hand of the World Nobles or the Celestial Dragons. Because the Celestial Dragons were the descendants of the founders of the World Government, the Celestial Dragons are granted a lot of money and can do whatever they want. The World Government knows about the Celestial Dragons but it still allows them to be within the law no matter how cruel the Celestial Dragons can be.

As a powerful and well-trusted organization by many people in the world, it would like to be seen as powerful. Leaders of the World Government would eliminate anyone who is too weak to enforce its power such as secretly hiring Donquixote Doflamingo to assassinate Gekko Moriah after the Marineford war. The World Government also want to be seen as something perfect and would lie to the public to make sure of it. For example, it covered up the fact that dangerous criminals have escaped from Impel Down to the public so that it can maintain its trust with the people. The World Government can be very secretive about its past and would prevent anyone from studying the Poneglyphs (giant stone tablets). And if anyone at least disobeys this rule then they are now one of the primary enemies of the world. For this reason, there is something about the World Government that the Gorosei do not want the world to know.