In 18 BBY, a lieutenant who was human and working for the Galactic Empire was stationed on the Sovereign. He reported directly to Governor Wilhuff Tarkin.
The human lieutenant was serving on the Sovereign, an Imperial I-class Star Destroyer, in 18 BBY. At that time, Governor Wilhuff Tarkin had been tasked with managing the military response to increasing tensions with the Outer Rim world of Mon Cala. The lieutenant was present on the bridge when information arrived about the status of negotiations that Ambassador Telvar was conducting with Lee-Char, the King of Mon Cala. The lieutenant informed Governor Tarkin that Telvar would soon be returning to the Sovereign. When Tarkin inquired about the negotiations' progress, the lieutenant relayed Telvar's assessment: "negotiations unproductive, but ongoing." Governor Tarkin acknowledged this, stating to the lieutenant that a diplomatic resolution was preferable. A crew member then notified Tarkin that a Zeta-class shuttle, identified as the Infernum via transponder, was approaching. Tarkin authorized its landing. When the lieutenant questioned Tarkin's familiarity with the vessel, Tarkin confirmed he knew it and that it represented a very different kind of diplomacy.
Following the explosion of Telvar's Lambda-class T-4a shuttle, the lieutenant reported to Tarkin that their sensors had detected an explosion shortly after takeoff, indicating a total loss. Tarkin inquired about the nature of the explosion, to which the lieutenant responded that they were still analyzing the data. Tarkin then instructed the lieutenant to inform Major Rantu to prepare landing craft for deployment upon receiving a signal. He also directed the lieutenant to notify Colonel Bergon and Commander Jordo to commence their respective phases of the operation.
After the invasion of the planet began, and the Battle of Dac City was underway, King Lee-Char and his military forces evacuated all civilians from the cities on the planet's surface. When the evacuations were approximately half complete, King Lee-Char contacted the Sovereign to protest the military action. He stated that they were not responsible for the death of Ambassador Telvar and that any further Imperial attacks would be met with strong resistance. After the unsuccessful conversation, Tarkin instructed the lieutenant to contact Rantu and inform him to anticipate a large-scale counterattack from the native forces, timed to coincide with the full evacuation of the civilian population. When the lieutenant inquired if he should provide Rantu with details about the attack, Tarkin responded that while he didn't know the specific tactics the natives would employ, the Empire was fully aware of their military capabilities. Mon Cala forces would use massive oceanic creatures, launching them out of the water to crash down near the surface cities, destroying both the cities and the Imperial forces stationed there.
The character of the Imperial lieutenant, though unnamed, made his first appearance in the 2018 canon comic book Darth Vader (2017) 13. The comic was written by Charles Soule with art by Giuseppe Camuncoli.