Most people say the Galactic Empire lasted “until Endor,” and that’s not wrong—but it’s not the full answer either. Palpatine dies in 4 ABY, yet the Empire doesn’t instantly vanish with him. It fractures, it bleeds territory, and it keeps fighting until it’s officially ended after Jakku in 5 ABY. So the real question isn’t just when the Emperor fell—it’s when the Empire stopped existing as a government.
How Long Did the Galactic Empire Last?
In Canon, the Galactic Empire lasted 24 years — from 19 BBY to 5 ABY.
It begins in 19 BBY, right at the end of the Clone Wars, when Palpatine issues Order 66 and reorganizes the Republic into the first Galactic Empire.
And it ends in 5 ABY, after the Empire’s defeat at the Battle of Jakku, when Mas Amedda signs the Empire’s surrender terms (the Imperial Instruments of Surrender) and the Galactic Concordance, which formally ends the war and closes the Empire as an official state.
Empire’s End even spells out that this one signature is what makes the Empire’s “death” official—Mas Amedda comes out of hiding and is “free to sign a meaningful Imperial Instrument of Surrender.”
Mon Mothma demands the signing happens on Chandrila, specifically on the crystal cliffs north of Hanna City, under an ancient tintolive tree—a deliberate choice, because it’s the same world the Empire attacked on Liberation Day. Leia is there too, and Mon is flanked by her advisers Sinjir Rath Velus and Sondiv Sella as the ceremony takes place.
And the terms aren’t symbolic. The book explains that the Instrument of Surrender (which informs the Galactic Concordance) demands that all Imperial fighting cease and that the Imperial government dissolve immediately—that’s the moment the Empire stops existing as an official state, not just a military threat.
How Long Did It Take Palpatine to Prepare the Empire?
If we zoom out, the “24 years” of the Empire is almost the short part. The preparation is where Palpatine actually spends most of his life.
In Legends, Darth Plagueis shows that Sidious and Hego Damask (Darth Plagueis) were already shaping the Republic for decades before the Clone Wars ever begin. The book straight-up frames their work as long-term “machinations” that wouldn’t be recognized “for decades to come,” while Palpatine spends twenty years sitting through Senate sessions and building the political life that will eventually carry him to the top.
And it’s not vague either, the plan is paced like a countdown. When Damask speaks to Sifo-Dyas, he predicts the Republic has “fifteen years at the most” before civil war and secessions start tearing it apart. In other words, they’re not waiting for a war to happen—they’re engineering the conditions so the Republic will beg for the “solution” Palpatine is going to offer.
The book also makes it clear this isn’t a sudden pivot—it’s a partnership built on slow control. Sidious grows stronger “over the decades,” while the two Sith dedicate themselves to executing the Grand Plan: manipulating real-world politics while tightening their grip on the Force.
So if you’re asking how long Palpatine “prepared” for the Empire, the answer isn’t a couple years before Episode III. Even just looking at his political groundwork in the novel, it’s decades of positioning, bribery, crisis-making, and long-game manipulation—so that when the Empire is finally declared, it doesn’t look like a conquest. It looks like the galaxy’s “only option.”
Bonus: How Long Did the New Republic Last?
In Canon, the New Republic lasted about 29 years — from 5 ABY to 34 ABY.
It rises out of the Rebel victory and becomes the galaxy’s new government as it rebuilds the Senate and locks the post-war peace in place through the Galactic Concordance. StarWars.com’s databank even frames the New Republic’s early identity around that treaty and the choice to demilitarize afterward
In 34 ABY, the First Order uses Starkiller Base to destroy the Hosnian system, including Hosnian Prime, which is described as the New Republic’s capital—an event that effectively wipes out the Republic’s government in one shot during The Force Awakens era.