- "You were deceived. And now, your Republic shall fall."
- ―Darth Malgus —
The Sacking of Coruscant, also known as the Battle of Coruscant, occurred at the end of the Great Galactic War between the Galactic Republic and the resurgent Sith Empire. Centuries after the supposed destruction of the original Empire, a surviving faction of the Sith returned from the Unknown Regions and waged a massive war against the Republic. After decades of fighting, the Republic was overwhelmed and inundated both economically and militarily, while the Empire continued to gain ground. At what seemed to be the height of their campaign, the Sith surprised the galaxy and extended an offer of peace to the Republic. Although cautious of the Empire's intentions, the Galactic Senate of the Republic accepted the much-needed reprieve. Unbeknownst to the Republic, the Sith had no intention of allowing the war to come to a peaceful conclusion.
While Republic and Imperial delegations convened on Alderaan for treaty negotiations, the Imperial-employed Mandalorian Shae Vizla traveled to the Republic capital world of Coruscant and deactivated the planet's defense grid. This allowed for the Sith Lord Darth Malgus to enter the Jedi Temple alongside a group of fifty Sith Warriors and lay siege to the ancient edifice. The Warriors had a violent altercation with the Temple's Jedi defenders, led by Master Ven Zallow, but were victorious in their mission. With the Jedi defeated, a fleet of Sith warships under the command of the Lord Darth Angral descended upon the planet, bombarding the cityscape and deploying Imperial soldiers and warriors to the surface. Although the surviving members of the Jedi Order and the Republic Special Forces Division attempted to defend their capital, the Sith forces overwhelmed them. By the time the fighting had ended, the Jedi Temple had been reduced to rubble, six members of the Jedi High Council had been killed, and Lord Angral had assassinated the Supreme Chancellor of the Republic. All communications into and out of Coruscant were locked down, leaving the rest of the galaxy to guess at the carnage that was unfolding on the surface.
For two days, the Empire blockaded Coruscant and occupied the world, ruling it under martial law. The Coruscanti people were prohibited from leaving the world, and travel across planet was heavily restricted. Darth Angral became the provisional governor of Coruscant, while his subordinate, Darth Malgus, oversaw the orbital security. During this time, the Sith looted the world, executed Republic senators, and kidnapped a number of locals. On the second day of the occupation, renegade Jedi Knight Aryn Leneer targeted Malgus for his hand in the destruction of the Jedi Temple. Her hunt led to a number of breaches in the security of the Sith quarantine force, but the Imperial hold over Coruscant remained. It was estimated by both Sith and Jedi that the death toll lay somewhere between the tens of thousands and one hundred thousand.
With the Republic's capital securely in their grip, the Empire was able to take command of the negotiations on Alderaan. After the two-day long occupation and the destruction of much of Galactic City, the Republic delegation was forced to sign the controversial Treaty of Coruscant. Although it brought an end to the Great Galactic War and returned the capital to its original occupants, the treaty's highly biased mandates set the stage for the Cold War and forced the Republic into a debilitating position of weakness within the galaxy. As such, reconstruction of Coruscant was delayed and then drawn out for several years, with residents in the poorer areas of the planet being forced to make a living in the ruin left behind by the Sith. The planet's lower levels fell under gang control, and were largely ignored by the Republic government, which was headquartered on the very same world.