The Commenor conflict happened in the time of the Second Galactic Civil War.
The Galactic Alliance's goal was to keep the Commenorian armies in check, rather than taking over the planet.
As the battle raged, components of the Galactic Alliance Third Fleet stealthily propelled a disguised asteroid towards Commenor. The pilots Caregg Oldathan and Danen from Grayfeather Squadron looked into the situation and found the disguised asteroid.
Understanding that stopping the collision with their planet was impossible, they chased after the ships that launched the attack, wanting revenge and to stop the tactic from being repeated.
Because of the horrible act that occurred during the battle, the Commenorians retaliated by unleashing the affliceria bacterium upon Coruscant, infecting a large number of both civilians and military personnel.