Declaration of the Rebel Alliance

As the Clone Wars neared their end between the Galactic Republic and the Confederacy of Independent Systems, Supreme Chancellor Sheev Palpatine progressively amassed emergency powers from the Galactic Senate. In response to these developments, concerned senators established the Delegation of 2,000, aiming to curb Palpatine's growing influence. This group advocated for the relinquishment of emergency powers and the repeal of the Sector Governance Decree, as well as promoting cease-fire negotiations with the Confederacy, regularly convening at the Cantham House meetings.

Ultimately, Palpatine accused the Jedi, guardians of peace in the galaxy and leaders within the Republic Military, of treason, and suppressed a fabricated Jedi rebellion. Palpatine, secretly the Dark Lord of the Sith Darth Sidious, dispatched his newly appointed Sith apprentice, Darth Vader, to Mustafar to eliminate the Separatist Council and deactivate the Separatist droid armies, thereby concluding the war.

Capitalizing on the chaos of the war and the elimination of the Jedi, Chancellor Palpatine declared a new order, transforming the Republic into the Galactic Empire, with himself as the Galactic Emperor. The following day, Imperial Intelligence launched a crackdown on Palpatine's political opponents, resulting in the mass arrest of 63 senators, many of whom were members of the Delegation of 2,000.

Senators like Mon Mothma and Bail Organa, who remained in the Imperial Senate, continued to oppose the Emperor politically and began monitoring early resistance movements against the Empire, including the Raada resistance. Over the years, more rebel cells emerged and began collaborating. By 5 BBY, Bail Organa routinely monitored these groups, with Fulcrum, secretly Anakin Skywalker's former padawan, Ahsoka Tano, assigning them missions. Following a skirmish above Mustafar, operational strategies shifted, leading to closer collaboration between rebel cells such as Phoenix Cell and the Spectres.

Insurrections also took hold in the Atrivis sector, involving the Liberators and the Atrivis Resistance Group. The Liberators suffered a devastating defeat against the Imperial Navy after seizing a garrison on Mantooine. After careful consideration, the Atrivis Resistance Group chose to join Mon Mothma in a rebel alliance she named "the Alliance."

After years of unsuccessful attempts to limit Palpatine's power and witnessing atrocities such as the Ghorman Massacre, where peaceful protestors were slaughtered, Mon Mothma publicly denounced the Emperor and resigned from the Senate. This act made her a prime target for the Imperial Military, labeling her a traitor, and the Imperial Security Bureau issued an alert for her capture. ISB agents also investigated Cantham House on Coruscant, the site of the Cantham House meetings, based on their suspicions, and questioned Leia Organa and others present.

Under Senator Organa's direction, Captain Hera Syndulla, Lieutenant Commander Ezra Bridger, and Captain Garazeb Orrelios aboard the Ghost, a modified VCX-100 light freighter owned by the Spectres of Phoenix Squadron, met with Gold Squadron of Massassi Group, who were escorting Mon Mothma to safety aboard the Chandrila Mistress for refueling. However, the Ghost had been previously detected by an Imperial E-XD-series infiltrator droid, dispatched by Grand Admiral Thrawn, tasked with locating Mon Mothma.

As refueling neared completion, Imperial forces ambushed them, resulting in the destruction of the Chandrila Mistress and forcing the rebels to retreat through the Archeon pass. They were soon ambushed again by a second Imperial force, including the new TIE/d "Defender" Multi-Role Starfighter, compelling the rebels to flee through the Archeon Nebula to evade their pursuers. This maneuver allowed the rebels to escape, but the Ghost and two Y-Wing bombers were separated.

Two Imperial I-class Star Destroyers, commanded by Arihnda Pryce, Governor of the Lothal sector, and Admiral Kassius Konstantine, arrived and ensnared the Ghost in a tractor beam. Imperial forces were defeated when Ezra Bridger and Gold Leader Jon Vander, piloting the two bombers, launched Proton torpedos at the Nebula, triggering an energy release that damaged the Star Destroyers and allowed the surviving rebels to break free.

Following the skirmish, the Ghost, with the two Y-Wings attached, emerged from hyperspace above the forested world of Dantooine in the Outer Rim. As the Ghost prepared to transmit, the rebels gathered in the cockpit, and Mon Mothma began her address. Her speech was broadcast across all rebel communication channels and on HoloNet channels accessed via satellites, ensuring that her call to arms reached trillions of beings throughout the galaxy, as well as established resistance groups like Phoenix Cell, Massassi Group, and the Lothal resistance group.

Shortly after Mon Mothma's call for an alliance, a CR90 corvette appeared from hyperspace, quickly followed by several more CR90s and Sphyrna-class Hammerhead corvettes. Eventually, numerous vessels emerged from hyperspace, including Home One and Phoenix Nest.

In the wake of the Declaration of the Rebel Alliance, the Alliance to Restore the Republic was officially established, and its various branches and units were structured. The Alliance comprised two main sections: the Alliance Civil Government, led by Mon Mothma as Chancellor and Chief of State, consisting of civilian bodies such as the Alliance Cabinet and Propaganda Bureau; and the Alliance Military, with Mon Mothma as the Commander-in-Chief, directed by Alliance High Command and its subordinate units. The Declaration of Rebellion was delivered to the Emperor, formally declaring open resistance between the Alliance and the Galactic Empire.

The declaration is regarded as the formal starting point of the Galactic Civil War, although the precise date of its commencement remains a subject of debate among later historians. Two years later, the Alliance achieved a significant victory by stealing the plans for the Death Star, a planet-destroying battle station, at the Battle of Scarif. These plans were instrumental in destroying the battle station at the Battle of Yavin. Despite facing major setbacks, such as the Mid Rim Retreat and the Battle of Hoth, the Alliance continued its campaigns against the Empire, which had begun construction of a second Death Star.

The second Death Star was subsequently destroyed in the Battle of Endor, which resulted in the defeat of the Imperial Navy, the death of Emperor Palpatine, and the Declaration of a New Republic, formally establishing the New Republic government.

Despite Imperial operations like Operation: Cinder, aimed at devastating loyal Imperial worlds, and the fragmentation of the Empire into various remnants, the Empire was ultimately defeated in the Battle of Jakku, between the New Republic and the Empire under Counselor to the Empire Gallius Rax. Following Rax's defeat, Grand Vizier Mas Amedda, who had been rendered powerless by Rax, signed the Galactic Concordance and the Imperial Instruments of Surrender, effectively ending the war and dissolving the Galactic Empire, which then fragmented into numerous independent governments, including Coruscant's provisional government.

Decades afterwards, the First Order arose from pro-Imperial factions, including a faction formed after the Galactic Concordance. The First Order evaded detection by the New Republic, building up its forces in the Unknown Regions, and destroying the New Republic in one decisive blow. This left the Resistance, a paramilitary force led by General Leia Organa, adoptive daughter of Bail Organa, to oppose the First Order. Despite suffering significant losses, the Resistance remained steadfast in its opposition.

During the conflict against the First Order, General Organa acquired The Rebel Files, a central archive containing various documents, including Mon Mothma's account of the moments leading up to the Declaration of the Rebel Alliance.

The Declaration of the Rebel Alliance was first presented in "Secret Cargo," the eighteenth episode of the third season of Star Wars Rebels, which premiered on March 4th, 2017. It was officially recognized and named as an event in Star Wars: The Rebel Files, a 2017 reference set by Daniel Wallace. In the Star Wars Legends continuity, the Corellian Treaty marked the official formation of the Rebel Alliance, first mentioned in The Rebel Alliance Sourcebook, a 1990 roleplaying sourcebook by West End Games and Paul Murphy, and first appearing in the 2008 novelization of The Force Unleashed.