Sector 3 served as the operational battlegrounds for the Republic 3rd Sector Army throughout the duration of the Clone Wars. Following the issuance of the Declaration of a New Order, it underwent restructuring to become an Imperial Priority Sector, with Grand Moff Kohl Seerdon assuming governance.
By the time of the Declaration of a New Order, Sector 3 had been restructured. In 19 BBY, its boundaries reached as far as Kashyyyk within the Mytaranor sector, and it was overseen by a regional governor whose base of operations was located on Bimmisaari in the Halla sector.