Declaration of the Rebel Alliance

"This is Senator Mon Mothma, I have been called a traitor for speaking out against a corrupt Galactic Senate. A Senate manipulated by the sinister tactics of the Emperor. For too long I have watched the heavy hand of the Empire strangle our liberties, stifling our freedoms in the name of ensuring our safety. No longer! Despite Imperial threats, despite the Emperor himself, I have no fear as I take new action. For I am not alone. Beginning today we stand together as allies. I hereby resign from the Senate to fight for you, not from the distant hall of politics but from the front lines. We will not rest until we bring an end to the Empire, until we restore our Republic! Are you with me?"

- Mon Mothma to the various rebel cells

The Declaration of the Rebel Alliance marked the official formation of the Alliance to Restore the Republic from the various rebel cells that formed the early rebellion. After a daring pursuit by Imperial forces, Senator Mon Mothma made a speech from the Ghost on all rebel communications channels and on HoloNet broadcasts where rebel forces could slice into, in which she resigned from the Imperial Senate and condemned the actions of the Galactic Emperor Sheev Palpatine. She continued and called for an alliance to restore the Galactic Republic, vowing to not rest until the Empire had been defeated. Following the speech, dozens of rebel starships, including Home One, Phoenix Nest, EF76 Nebulon-B escort frigates, CR90 corvettes, and Hammerhead corvettes, emerged from hyperspace above Dantooine, answering the call to action.

Behind the scenes
The Declaration of the Rebel Alliance first appeared in the eighteenth episode of the third season of Star Wars Rebels, named Secret Cargo, airing on March 4, 2017. It was officially named and marked as an event in the boxed set Star Wars: The Rebel Files – Deluxe Edition