Early in the rule of the Galactic Empire, the Imperial Army deployed soldiers separate from stormtroopers. They were often members of local planetary defense forces who fought during the Clone Wars and were conscripted into the Imperial Military. The Imperial Army gradually upgraded and replaced the soldiers with stormtroopers.
In 14 BBY, non-stormtrooper soldiers fought under Moff Delian Mors against the Free Ryloth movement. Swamp troopers were soldiers of the Imperial Army that were classified as regular infantry, and not stormtroopers. During the Mimban campaign in 10 BBY, swamp troopers fought alongside Mimban Stormtroopers against the Mimbanese Liberation Army.
- Solo: A Star Wars Story The Official Guide (Indirect mention only)