The Battle of Czerka 431 was a minor battle that occurred during the Jedi Civil War.
Following the Czerka Corporation's alliance with the Sith Empire, the Sith took direct control of the secret research facility, Czerka 431. There, they forced the scientist Joni Ree to perform experiments on Juggernaut war droids. She disliked her new employers, so she contacted the Galactic Republic and gave them the location of the facility. She learned from them the scheduled time of their attack on it, so she could co-ordinate her escape attempt with this. Ree knew that the Sith would try to stun her during an escape attempt, so she also created a device to revive herself from such an attack.
The Republic sent a total of six troopers, and Ree was able to break out with the help of two Juggernaut droids, which came as a surprise to the Sith. The Sith troops responded by trying to kill all the Republic forces and capture Ree alive. However, Ree was able to escape and started working for the Republic.