The First Battle of Coruscant was the largest and most costly battle in the One Sith War. After the Battle of Dromund Kaas, the One Sith Empire was fully pepered the attack Corusant. With a powerful attack force and a devistating plan, the Empire took the city planet in a mater of hours after the invasion started. After the battle, the Empire attacked and conquered many Core worlds in the Alliance's state of weakness. This battle drove the Alliance Core forces to retrete to worlds much farther than the Core, most Mid and Outer Rim worlds under their control.