The First Battle of Coruscant, also called the Invasion of Coruscant, was the first battle of the Alsakan Crisis in 13,000 BBY. Taking place between the Alsakan Union and the Galactic Republic, the battle resulted in the Galactic Senate fleeing from Coruscant after the Alsakans invaded. This effectively made Coruscant a territory of the Alsakan Union, something that had been a goal of theirs for centuries.
The battle traced its origins back to a diplomatic meeting on Coruscant thousands of years earlier between the Republic and the Alsakans which both sides claimed to be disastrous. The Vicar of the Alsakan Union at that time had traveled to Coruscant for the meeting, and was taken ill when she saw the urbanization and globalization that had taken away the planets natural resources. This left her so ill that it eventually killed her, causing high tensions between the two governments. After this event, the Alsakan Union created a goal to take Coruscant away from the Republic and begin a terraforming process to, as the Alsakans said, restore nature to the planet.
Shortly before the battle began, the Alsakans blockaded the hyperspace lanes surrounding Coruscant, leaving only one open. However, they placed gravimetric mines at the exit to the route, and when the Republic forces exited from it they received damage from the cascading explosions. The Alsakans outnumbered the Republic in their forces, and as they fought the Galactic Senate debated whether or not they should evacuate Coruscant. Some members of the Senate, such as Supreme Chancellor Relana Isolde Tanoor and Alderaanian Senator Alcor Bac, voiced their support for an evacuation while others such as Corellian Senator Judah Matthew Zaren were very vocal in their opposition. In the end, the supporters were the majority vote and the Alsakans allowed the Senate to leave as the Republic military also fled.
Once Coruscant was under Alsakan control, they began their terraforming projects to restore the natural environment to the planet. The Republic set up a new base on Ord Mirit to begin planning retaliatory attacks, though the Jedi Order attempted to work with both sides to negotiate a peace before the conflict became a full-scale war. Coruscant remained under Alsakan control for months, though after the assassination of the Alsakan Vicar Lharra the Republic launched an attack on Coruscant which returned control of the planet to them. Despite this, the war continued on.
After the foundation of their alliance with the Tae, the commanders of the Alsakan Union believed that they were ready to begin a more proper war effort against the Galactic Republic, as their previous efforts had failed. Believing that the best course of action was a bold one, the military leaders of the Union planned a massive invasion of Coruscant in an effort to take the planet away from the Republic quickly while the element of surprise was still on their side.
The Alsakans knew that the war would not end there, as the Republic would likely carry out a counter-attack, but they felt that if they could accomplish their main goal before hand then the war would be short. Lharra, the Vicar of the Alsakans who had been told of atrocities on Coruscant such as children and other people being mistreated and the so-called horrors of the globalization, approved of the plan and she gave her blessing for it to be carried out.
What Lharra did not know was that the stories she was being told about Coruscant were highly exaggerated. Her circle of advisers and caretakers knew that while Coruscant did have faults, they were not nearly as bad as what they were telling her. Because Lharra was only a young girl, her advisers, who some said were more radical than other Alsakans, knew that they would be able to manipulate her to the point of her approving their radical plans. They also decided amongst themselves that they would not hesitate to do all that was necessary to achieve their goals.
Once the Alsakans prepared their vessels, they sent out a group of them that had been somewhat modified to resemble Republic warships, and their transponder codes had also been altered to resemble a Republic vessel for when they were detected. Once these vessels arrived around Coruscant, they destroyed all of the hyperspace beacons around the planet in order to cut off a potential Republic escape attempt. Shortly thereafter, the rest of the fleet that was ordered to participate arrived and began fighting the small Coruscant defense fleet.
The Coruscant defense fleet called in reinforcements from wherever they could, but they noted that they would only have the one hyperspace lane to travel through. The Alsakans also knew this, so without the defense fleet’s knowledge the Alsakans placed a large group of mines where the Republic would exit hyperspace to fight them. Once the Republic vessels arrived, they fell victim to this trap and the mines exploding, greatly crippling their fleet to the point where both sides recognized that the Alsakans had a clear advantage through their superior numbers.
While the battle was progressing, the Galactic Senate was called into an emergency session by Supreme Chancellor Relana Isolde Tanoor. She recommended having the Senate evacuate Coruscant, which the Alsakans were going to allow, and have all Galactic Senators return to their home worlds before being told where a new location for the capital would be established. Many Senators, such as Corellian Senator Judah Matthew Zaren, did not agree with this as they felt that the battle could still be won by the Republic and they did not believe it was a proper to leave the people of Coruscant in the hands of an enemy force. Others such as Alderaanian Senator Alcor Bac, however, felt that it was important to ensure the survival and effectiveness of the Senate and that the only way to do this was to move off world. The majority of the Senate agreed with the side argued by Bac, and it was agreed that Tanoor would be given the right to decide where the emergency location would be.
As the Senate was evacuating, thousands of Republic and Alsakan fighters were filling the skies of Coruscant, fighting against one another in an effort to gain an upper hand. However, the Alsakans continued to hold the advantage due to the events that had taken place in the beginning of the battle, and the efforts of the Union forces eventually proved too much for the Republic. In order to cut their losses, the Republic agreed amongst itself to order a retreat to other Core Worlds. The evacuating Republic forces were also able to provide cover for the Senators that were evacuating in the event that the Alsakans decided to attack them. After many hours and casualties, the Alsakans had won their victory of the Republic and Coruscant was officially in their possession.