An insurgency unfolded within the Batonn sector, pitting a collection of rebellious factions from the planets Batonn, Denash, and Sammun against the oppressive governance of the Galactic Empire. This coalition of insurgents was spearheaded by the enigmatic Nightswan, a clandestine leader of the rebellion with the aim of toppling the Empire. The insurgency in the Batonn sector met a violent conclusion during the siege of the Creekpath Mining and Refining complex situated on Batonn. With Nightswan's death at that location, the remaining insurgents dispersed into the vastness of space. In recognition of his pivotal role in suppressing the rebel presence within the Batonn sector, the Emperor elevated Thrawn to the rank of Grand Admiral and entrusted him with the command of the Seventh Fleet.
During the Imperial Era, the pirate and insurgent leader Nevil Cygni, known as "Nightswan," orchestrated an insurgent campaign aimed at undermining the authority of the Galactic Empire, which he denounced as a corrupt and tyrannical regime. Nightswan engaged in diverse illicit activities, such as smuggling valuable resources like doonium, iridium, and tibanna, using the proceeds to finance his anti-Empire efforts. Nightswan's acts of rebellion included the clandestine operation of a spy ring based on Coruscant and the liberation of enslaved Wookiees. Nightswan's actions garnered the attention of several key figures, including the Chiss Imperial Navy officer Mitth'raw'nuruodo, his associate Eli Vanto, Imperial Security Bureau Colonel Wullf Yularen, and the ambitious Lothalite Governor Arihnda Pryce.
Following the attempted secession of Botajef, the Batonn insurgents under the command of Nevil Cygni seized control of the Imperial garrison stationed on Scrim Island, taking its personnel as hostages. In response, Fleet Admiral Jok Donassius dispatched Admiral [Durril] to reclaim the island. Durril's One Oh Third Task Force encountered fierce resistance from the insurgent forces on Scrim Island and was ultimately repelled. Simultaneously, other units of the Imperial Navy, under the leadership of Admiral Kinshara and Commander Karyn Faro, successfully neutralized the insurgent factions operating on Denash and Sammun. However, a significant portion of the Denash insurgents managed to escape to the Creekpath Mining and Refining complex on Batonn, where they joined forces with Nightswan's Batonn-based insurgents.
Later, Thrawn's 96th Task Force skillfully employed strategic maneuvers to overcome Scrim Island's defenses, compelling the insurgents there to surrender. Thrawn's efforts to peacefully resolve the siege at the Creekpath complex were thwarted by an operation conducted by the Imperial Security Bureau, which involved planting explosives within the facility. Governor Pryce then detonated these explosives to conceal her murder of ISB Agent Gudry. The resulting massive explosion decimated the Batonn insurgents and resulted in numerous civilian casualties.
Despite the extensive loss of life, the pacification of the Batonn sector was hailed as an Imperial triumph, as it effectively eradicated the rebel presence in the region. In recognition of his contributions, the Emperor promoted Thrawn to the esteemed rank of Grand Admiral and entrusted him with the command of the Seventh Fleet. Due to Thrawn's exceptional reputation, Governor Pryce sought his assistance in combating the Phoenix Cell and the Spectres rebel cell operating within the Lothal sector. Following a sustained campaign, Thrawn successfully located the Phoenix Squadron's base on Atollon and inflicted substantial losses on the rebels during the Battle of Atollon.
The Batonn sector insurgency was first alluded to in the Star Wars Rebels Season Three television film Star Wars Rebels: Steps Into Shadow, which premiered at Celebration Europe on July 16, 2016. It was later featured in Timothy Zahn's 2017 novel titled Thrawn.