During the Clone Wars, the 20th Sector Army fought a back-and-forth war with Separatist forces along the Rimma and the Corellian Trade Spine, especially near the Separatist strongholds of Thyferra and Bestine. Near the end of the war, the 20th gained the upper hand when General Grievous pulled many of the area's assets out of the region to use in his raid on Coruscant.
When Supreme Chancellor Palpatine declared himself Emperor, Emerald Banner Command became part of the Imperial Military. By 2 BBY, Emerald Banner Command was under the control of the newly-appointed Grand Admiral Octavian Grant.
- The Essential Guide to Warfare