A significant conflict unfolded on the planet of Denon in 6 ABY. This event took place during the New Republic's campaign to liberate planets following the Battle of Endor.
Just one month following the Battle of Endor in 4 ABY, the New Republic initiated operations aimed at freeing the galaxy from the control of the Galactic Empire. The Fourth Fleet, led by Admiral Voon Massa, launched its efforts from the New Republic stronghold in Bothan Space and ventured into the Slice. They successfully seized the strategically important industrial world of Druckenwell located along the Corellian Run in 4 ABY. Then, in 5 ABY, they engaged in the arduous three-month Milagro campaign, battling Imperial forces commanded by Admiral Uther Kermen.
Following their success in securing the Milagro system, the Fourth Fleet moved forward and captured the Spirana system from the Galactic Empire. This victory provided the New Republic with a valuable strategic position within the Inner Rim, where they regrouped to prepare for the next phase of their offensive in the coming year.
In 6 ABY, the New Republic's Fourth Fleet proceeded from Spirana into the Denon system, where they clashed with Admiral Kermen's Imperial forces above the ecumenopolis world. This confrontation was a brutal and intense struggle. Admiral Massa lost his life during the battle, but his second-in-command, Admiral Chel Dorat, managed to break through the Imperial defenses, forcing Admiral Kermen to retreat from the system.
This hard-won victory for the New Republic extended their reach along the Corellian Run to the border of the Colonies and ensured control over the intersection of the Run and the Hydian Way. Combined with the First Fleet's defeat of Warlord Prentioch at Bomis Koori IV, and the Third Fleet's triumphs at Reytha and Uviuy Exen, the capture of Denon furthered Admiral Gial Ackbar's strategy to surround the Core Worlds as a precursor to the capture of Coruscant.