The 481st Legion was a legion of the Grand Army of the Republic that was active at the end of the Clone Wars during Order 66. As part of Order 66, elements of the 481st Legion were dispatched to Ilum to secure the Jedi Temple there and eliminate any Jedi survivors from the initial onslaught. Once the Galactic Republic transitioned into the Galactic Empire and Emperor Palpatine had firm control of his Empire, the 481st Legion was rotated out and recalled to their home unit and replaced by a joint Army and Naval garrison and blockade. Eventually the forces on Ilum would be supplanted by inefficient equipment and unreliable officers despite Palpatine's insistence on Ilum's importance and the growing size of the garrison. The blockade would constantly see rotations of squadrons of varying sizes.
- Nexus of Power (First mentioned)