In 14 BBY, the rebel cell led by Berch Teller initiated an assault on the Galactic Empire's Sentinel Base. The rebels, utilizing communication devices provided by Vice Admiral Dodd Rancit, disseminated a fabricated holotransmission, falsely indicating that Rampart Station was under siege. Tarkin, however, discerned the deceptive nature of the message and promptly dispatched his Venator-class Star Destroyer, the Electrum, on a microjump to the system's outer limits. Shortly thereafter, a significantly altered Providence-class Dreadnought materialized within the system. Subsequently, Tarkin deployed the Venator, instructing it to execute an ambush on the incoming vessel. The Providence cruiser then made a hasty withdrawal into hyperspace.
By the year 14 BBY, Moff Wilhuff Tarkin held the position of authority over the clandestine Death Star project, a space station. At that juncture, the project encompassed multiple locations, notably Geonosis, Desolation Station, and Sentinel Base. Sentinel Base functioned as a relay station for supplies along a route culminating at Geonosis. Tarkin's promotion occurred at the expense of Vice Admiral Dodd Rancit, who was reassigned to the role of Director of the Naval Intelligence Agency, a division of Imperial Intelligence. Harboring resentment towards Tarkin's elevated status, Rancit secretly collaborated with Berch Teller, a former officer of Republic Intelligence and another adversary of Tarkin who despised the Moff for his involvement in the Antar Atrocity, an event involving the mass slaughter of numerous Gotal and Koorivar civilians, including loyalists, on Antar 4. Teller emerged as the leader of a group of dissidents who actively opposed the Empire.
Leveraging his influence and network, Rancit furnished the dissidents with forbidden weaponry, communication tools, and seized Separatist military equipment, including a Providence-class Dreadnought, Vulture droids, and droid tri-fighters. The modified Separatist warship underwent assembly at shipyards situated in the Bajic sector, with contributions from the Tenloss Syndicate and the Crymorah Syndicate. Teller additionally maintained a network of collaborators comprising workers, salvagers, and scientists who provided materials and intelligence to his cell.
While attempting to wear an Imperial officer's uniform, Moff Tarkin received an urgent communication from Rampart Station, indicating an ongoing attack on the station. By impersonating Lieutenant Thon, Teller's rebels had engineered a fraudulent holotransmission with the intention of diverting Sentinel Station's garrison away from the base. Upon scrutinizing the footage, Tarkin suspected the transmission's falsity but chose to keep his suspicions to himself. After verifying the base's inventory, Tarkin instructed the Venator-class Star Destroyer Electrum to execute a microjump to the Rimward edge of the Sentinel Base system. He ordered Captain Burque to maintain position there pending further instructions.
Shortly thereafter, Teller's warship emerged from hyperspace, releasing a contingent of Separatist-model droid starfighters. The presence of these droid starfighters prompted some Sentinel Base officers to speculate about a potential attack by a Separatist holdout. Tarkin directed Commander Cassel to initiate general quarters, amplify power to the base's deflector shields, and implement countermeasures. Under Tarkin's command, Sentinel Base's artillery commenced bombardment of the unidentified warship and its accompanying droid starfighters. Faced with the robust defense, the intruders initiated a retreat. Following the Electrum's return to realspace, Tarkin instructed Captain Burque to deploy his starfighters to harass the enemy droid starfighters and disable the carrier.
During the engagement, Tarkin received communication from Rampart Station's Commander Jae, who reported a malfunction in their base's HoloNet relay. Despite the Electrum's interventions, the enemy carrier successfully escaped into hyperspace. The remaining droid starfighters were eliminated by Imperial TIE fighters. Tarkin instructed Commander Cassel to dispatch a forensic team to analyze the enemy droid starfighters. While conversing with a specialist, Tarkin revealed his awareness of the holotransmission's counterfeit nature, citing the presence of interval noise in the replay. They concluded that an individual had managed to insert a fabricated real-time feed into the local HoloNet relay.
Following the unsuccessful assault on Sentinel Base, Moff Tarkin participated in a meeting of the Ruling Council on Coruscant. He and Darth Vader were dispatched by Emperor Palpatine to investigate a communications cache located on Murkhana. However, the communications cache proved to be a deception orchestrated by Vice Admiral Rancit to facilitate Teller and his cell's theft of Tarkin's personal starship, the Carrion Spike, which boasted an advanced hyperdrive and prototype stealth technology. Teller intended to utilize the Carrion Spike to launch attacks against various Imperial facilities along the Perlemian Trade Route as part of his campaign against the Empire.
The Sentinel Base assault functions as the exposition in James Luceno's 2014 novel, Tarkin, the second installment in the series of new Canon adult novels published by Del Rey. The battle's narrative unfolds from the perspective of the titular character, Tarkin.