- "If I remember my military history, wasn't he vaporized at the Battle of Malastare Narrows?"
- —Anakin Skywalker to Wullf Yularen on Trench
Before the Clone Wars, Trench made his mark on galactic military history as a commander for the Corporate Alliance. When the Alliance decided to blockade Malastare Trench was placed in command of the fleet the corporation provided and succeeded in defeating all the the ships sent against him. Wullf Yularen who was one of the few survivors of the battle recounted that the Harch Admiral's leadership was devastating. It would only be through the intervention of a Jedi lead taskforce that the Corporate Alliance blockade was ended. The Jedi defeated Trench's forces by destroying the Admiral's flagship while Trench was believed to be onboard. However the Harch naval genius in fact survived to reappear during the Separatist blockade over Christophsis.
Cat and Mouse
After the initial victory over the forces of Whorm Loathsom and the Retail Caucus, the Republic launched a relief effort for the people of Christophsis. The mission to help the Christophsians was led by Bail Organa, the Senator representing Alderaan. Unfortunately, the planet fell under attack from Admiral Trench and his forces. Trench's first priority was to cut off any supplies to the relief effort on the planet below, commanding his fleet from his very own war-painted Providence-class destroyer, the massive fire power of his cruiser allowed the Admiral to cripple any attempt by incoming supply ships to get to the surface. Such an attempt was made by Anakin Skywalker and his cruisers, the Jedi were met with suppressive fire from Trench's destroyer and were forced to retreat behind the moon of Christophsis.
While the Jedi retreated and regrouped, Trench felt he had won the round he ordered his troops not to follow the enemy, but to recycle their shields and allow the cannons to recharge to full power. The Admiral, satisfied with the proceedings, sat back in his seat at the bridge and calmly awaited for the return of the enemy ships. The Republic's counter-attack eventually came in the form of a Stealth ship, piloted by Anakin Skywalker himself and Admiral Yularen. Not knowing of the cloaked ship, Trench became impatient and ordered a number of Hyena-class bombers to attack the surface, particularly the command center of Bail Organa. The bombing was planned by Trench to draw out the hiding Republic "cowards", as he put it. Although the stealth ship was undetected by the Admiral, Trench suspected that there was something odd going on. His suspicions proved correct, when Anakin's ship presented itself and fired its torpedoes at Trench's cruiser. Unfortunately, the maneuver had little effect. Admiral Trench reacted quickly and raised his ship's thermal shields.
Angered by this act of foolishness, Trench responded by firing his own torpedoes at the stealth ship. Skywalker managed evade the torpedoes by ordering flairs shot in four different directions. As a result of the successful trick, Anakin Skywalker saved himself and his crew for now. After the engagement, the stealth ship went into hiding again. Unsure where the targeted ship was, the furious Admiral fired a spread of lasers, to no avail. Skywalker managed to navigate the "wave" of laser fire. Seeing how the short skirmish played out, Trench was now sure that they were not dealing with near clone pilots but with a Jedi. After which he patched a transmission on the comlink channel, so that he could present himself to his adversaries. Threatening the crew of the stealth ship and advising them to retreat while they still could. Trench ended the transmission with a warning that he would be their doom. Trench prepared himself for the Jedi's second offensive, as he knew they would. Eventually the cloaked vessel revealed itself, but this time they had knowledge of Trench's tactics with ship cloaking devices. Trench tracked the magnetic signatures of ships so he could follow them and destroy them. The Stealth ship opened fire upon Trench's flagship, the attack itself was only a diversion and Anakin's ship again cloaked itself. Trench then locked on to the ship's magnetic signature and ordered his Tactical droid to fire a torpedo at the source of the signature on his command. He was forced to lower his shields to do so. His droid advised against the move, but in a moment of compulsive anger Trench ordered to fire and the torpedoes were launched.
This had been the moment Skywalker was waiting for: the stealth ship, with torpedoes on its tail, turned around and headed towards the bridge of Trench's command ship. Surprised by the bold attack, the Admiral ordered the shields to be raised back up. Alas, the shields weren't recharged to full power and the ship was left defenseless. Trench was caught off guard and now seeing the Republic ship speeding towards him, the Admiral didn't know what to do and how to react. Accepting his defeat, he closed his six eyes and awaited his demise. The Stealth ship flew right over and the torpedoes slammed straight into the bridge, destroying Trench's flagship, and bringing chaos to the blockade. At that crucial moment, one of the most successful Confederate fleet Admirals lost for the Separatist cause.
Admiral Trench somehow managed to survive the destruction of his flagship again, requiring cybernetics for most of the left side of his body, and continued to serve the Separatists in battle.