During the high days of the Empire's reign, the Redoubt did not exist; all of the territory fell under the authority of Grand Moff Tarkin, governor of the Outer Rim Territories. However, after the Battle of Endor, much of the surrounding territory was lost to feuding warlords and incursions by the New Republic, or the worlds had simply overthrown their Imperial masters.
The Calaron Sector, including such worlds as Kessel, Honoghr, Kubindi, and Fwillsving, was an Imperial Sector ruled by the ruthless Moff Viker Windel, who, upon hearing of the Emperor's death at Endor, decided to declare his Sector autonomous and him its undisputed ruler. As worlds in the Outer Rim fell at a devastating pace to either the New Republic or to warlords such as Windel, the Calaron Sector found itself surrounded on all sides by enemies and potential enemies, such as the Hutts, whose territory bordered upon Windel's. Windel knew he had a major advantage, though: the infamous Maw was under his territory, and all the secrets that Tarkin had stashed away were within his grasp. He just did not know how to safely navigate the Maw, so he sacrificed many ships to find a suitable path: none worked.
Meanwhile, dissent brewed within Windel's ranks. One Millanos Sekirol, Admiral in charge of the Sector's fleet, was loyal to the New Order and had secretly established contact with the Sate Pestage of the Interim Ruling Council to see the Sector returned to Imperial rule. Pestage knew that the Sector would provide an invaluable resource to the Empire, offering them a position on the far-side of the galaxy with easy access to Dac and the spice mines of Kessel and the facilities of the Maw. Sekirol, winning over the loyalty of his crew, staged a coup against Windel, who was easily ousted and sent to live the rest of his days on Kessel. Sekirol was given complete control over the Calaron Sector and then began a series of campaigns to expand the territory. For the year of 5 ABY, Sekirol succeeded in expanding the Sector's territory, and the entire territory became dubbed the Kessel Redoubt, the only Imperial presence on that side of the galaxy.
The Redoubt was fortified heavily and for the next three years sustained constant incursions from both the Republic and various warlords, each seeking to wipe out the vestiges of the Empire. But Sekirol was cunning and his forces well trained; each attack was dealt with and forced into rout. No effort by the Republic or warlords ever succeeded, and the Redoubt remained a strong reminder of the Empire's continued existence and might.
When Bacharan Valak ascended the throne in 8 ABY, Sekirol's Redoubt would prove valuable in assaulting Dac during the Great Campaign, and for his actions for maintaining the Redoubt, Sekirol was awarded for his actions. Sekirol maintained control of the Redoubt, its territory expanded some since the Great Campaign. Sekirol would later provide assistance in bringing down his traitorous brother, Jorgen Sekirol, in the Moff Sekirol Crisis.Towards the latter of 16 ABY, the Kessel Redoubt became an important piece of territory for the Empire. Imperial forces routed troops, warships and supplies to the Redoubt as a staging area for operations against Mon Calamari during the Dacan Civil War. While Sekirol maintained control over his forces in the Redoubt, it is unlikely he had operational control over forces in use for operations against Calamari.