The Union of Allied Planets or Universal Alliance or Anglo-Sino Alliance, is the central government and law-enforcement organization of the Verse. In its present form, it came about after the Central planets fought the Unification War against the Independent Planets that wanted to break away from Alliance jurisdiction. The war raged for nearly six years. However, by 2511 the Alliance had prevailed, and an armistice was signed.
The Alliance is governed by a Parliament, the exact nature of which is unknown, and there may be at least a titular monarch, as Serenity's captain, Malcolm Reynolds has said "I'd like to be king of all Londinium", although this may have been a metaphor.
Londinium is the formal seat of government, home to Parliament and the Prime Minister. While every planet (at least within the Core) is allowed to organize its own affairs on a planetary level, system-wide policy is set by the Parliament. The planet of Sihnon is home to the headquarters of the trade associations and guilds in the system. The most powerful of these have their academies here.
Most people of the Alliance are allowed a say in their government. Anyone can stand for a seat in the Parliament and be voted in by the home folk. But the money required to run a campaign generally prevents the common man from ever winning a governmental position. To raise the necessary funds, candidates must make deals with businesses, guilds, and private interest groups. As to voting, only those who are "full citizens of the Alliance" actually get a vote. Folk who fought in or supported the Independents are not considered "full citizens." The reasoning behind this is that people who fought against the Alliance could not be trusted to vote for the right candidate. Thus only candidates who support the Alliance are ever elected. That law is due to expire after ten years, though there are some on the Core worlds who are pushing for it to be extended.
Planets are governed by Governors and moons by Magistrates. Prefects are also incorporated into the system of governance. The Alliance has given guidelines on how such a person is elected, but out of respect for the sovereignty of each world policies vary from place to place. Some Core worlds are fairly ruled by honest folk. On others, local political machines or long-standing family dynasties rule.
The dominant culture in the Alliance was a melding of those of the People's Republic of China and United States of America which occurred over the course of the long voyage from Earth-that-Was. The cultural hybrid is reflected in the flag that is inspired by China's and the United States' flags from Earth-That-Was. The Alliance is also comprised of other cultures, such as Muslims, Jews, Hindus, and Native Americans, who are a part of the social fabric. As a result, most people in the 'Verse are equally adept in speaking both English and Mandarin, and mix words from the two languages in normal conversation.
There are elements of feudal culture incorporated into society, as many of Companion Inara Serra's customers are referred to as Lords. Both slavery and indentured servitude are either legal, or tacitly overlooked by the authorities.
After Earth's natural resources were used up, mankind abandoned the planet (which now exists in myth and legend as "Earth-That-Was"), and moved out into the stars, while holding onto the tenets of culture and civilization, carrying with it those things both material and spiritual that tied it to their ancestral world.
Relatively little is known of the early history of the Alliance.
At the Battle of Serenity Valley (the last major battle in the Unification War), both the Alliance and the Browncoats suffered heavy casualties. Survivors from both sides were stranded on the battlefield until the Alliance was able to send a fleet of medical transports to rescue them.
The day that the civil war ended is known as "Unification Day" and is celebrated as a holiday throughout the system. Alliance supporters like to drink a toast to Unification Day and enthusiastically encourage others to join in the festivities, while singing the anthem of the Alliance. 
From Core to Rim, from sun to moon,
On this we all agree;
Like oxen yoked up to a cart
United we are free!
The men and women who serve in the military are well-trained and disciplined and are issued state-of-the-art firearms and body armor. However, like any other immense organization, the military has its share of blackguards, idiots, and scoundrels who can be bribed, bluffed, or fooled. And, yes, the occasional soldier might fall asleep on guard duty. But don't count on it. Most troopers in the Alliance military are dedicated and smart and know every trick in the book.
Just about every town on every planet and moon has some form of local law. In many cases, the law is a man with a tin star looking to keep everyone else in town honest. In others, the law is a bunch of brigands who go around breaking kneecaps on orders from the local governor or magistrate. Whatever form the local law takes, they tend to deal with petty theft and hooligans. When something major comes along - like the assassination of a governor or the kidnapping of a powerful Guild leader - the locals call in either Interpol or the Federal marshals.
Interpol (Interplanetary Police) deals with criminals who have fled the jurisdiction of local law enforcement, as well as crimes committed in areas that are outside local control, though still under Alliance control, which includes most of the known universe. Interpol generally deals more with tracking suspects and investigating interplanetary crime than direct enforcement. The enforcement of federal law and the pursuit of criminals across interplanetary borders falls under the jurisdiction of Federal Marshals.
Federal agents and Federal marshals (or simply, 'Feds') track down wanted criminals and/or bring to trial those who fail to answer a summons. Some Feds are righteous enforcers of the peace, but there are a few who are more bounty hunter than law enforcer and will go after anyone if the money's good enough. Since they have to travel a far piece to do their jobs, the Feds have a great deal of autonomy. Feds work alone or in teams. They are provided with excellent ships and equipment, though some choose to work undercover if they are on the trail of particularly dangerous (or lucrative) fugitives.
Regime weakened: "The Signal"
The crew of Serenity discovered the source of River's insanity while on the run from the Operative: in an experiment on the planet Miranda years ago, the Alliance inadvertently killed nearly 30 million people and created the first Reavers. River was exposed to this information after key members of Parliament were given a tour of the facilities where she was being held. Subsequent to that, her brother Simon Tam rescued her, and the government pursued the siblings to prevent this information from being revealed. The Alliance's main contractors, the Hands of Blue, took it upon themselves to find them, but were eventually killed, and the task was given to the Operative. Malcolm Reynolds decided to reveal the secret to the entire universe, heading to Mr. Universe's planet to do so.
However, the Operative was waiting for him, having anticipated this. Mal had a plan for this, however, and caused a distraction by firing on the Reavers, beginning the Universe battle between the Alliance and the Reavers while Serenity slipped past to the planet. Success came at a price: the ship suffered massive damage from an EMP and the landing, and Hoban Washburne was fatally impaled by a Reaver ship's harpoon. Mal located Mr. Universe's backup transmitter, but the Operative found him there. Mal disabled the Operative, but spared him in order to show him "a world without sin". He then broadcast the message to the entire system, destroying the Operative's faith in the Alliance's methods and making the existence of the Reavers, and thus the true colors of the Alliance, known to the people at large. After hearing this, the Operative orders his forces to let the crew of Serenity go, aids them in repairing the ship, and tells his superiors that Simon Tam and River Tam are no longer a threat to them (In one draft of the script, he mentions that the Alliance's officials have been getting multiple complaints from several worlds). He also tells Mal that, while the Alliance's regime is weakened, he could not guarantee that they would not continue to pursue him. It is also implied to a very limited extent that a new civil war could've begun to brew at the end of Serenity.
- Alliance Colony and Settlement Authority
- Allied Postal System
- Ministry of Intelligence
- Special Alliance Support
- Union of Allied Planets Army
- Union of Allied Planets Navy
- Firefly – "Serenity" (First appearance)
- Firefly – "The Train Job"
- Firefly – "Bushwhacked"
- Firefly – "Shindig"
- Firefly – "Safe"
- Firefly – "Our Mrs. Reynolds"
- Firefly – "Jaynestown"
- Firefly – "Out of Gas"
- Firefly – "Ariel"
- Firefly – "War Stories"
- Firefly – "Trash"
- Firefly – "The Message"
- Firefly – "Heart of Gold"
- Firefly – "Objects in Space"
- Better Days
- Those Left Behind
- Firefly - Big Damn Hero
- Serenity movie
- Serenity novel