The Sith fleet served as the space-based military component for the Sith, fighting on behalf of the Brotherhood of Darkness towards the end of the New Sith Wars.
Typical capital ships included Sith Dreadnaughts and other cruisers. However, Sith Destroyers, such as the flagship Nightfall, were likely even more formidable. Smaller corsair battleships also participated as attack vessels.
In addition to the larger warships, the Sith fleet utilized starfighters like the Buzzard and Sith interceptor, troop carriers such as the Interloper, and other smaller vessels like the T-class long-range personal cruiser.
Based on their designations, it seems many of these ship types were unique to the Sith fleet, suggesting they were manufactured in shipyards under Sith control, likely located in the Outer Rim, where the Brotherhood of Darkness enjoyed significant support.
Lord Kaan usually commanded the fleet directly from the Nightfall, while Admiral Adrianna Nyras held the highest naval rank. The naval personnel seemingly lacked Force-sensitive abilities, but the Sith fleet, particularly when empowered by Kaan's battle meditation, proved capable of challenging the Republic Navy in combat.
Their operational focus revolved around controlling planets. Offenses involved overwhelming Republic defenders in orbit before deploying Sith ground forces for surface engagements. Defensively, their tactics centered on preventing Republic forces from landing troops on Sith-held worlds.
The specific naval resources Kaan obtained from the warring factions he united into the Brotherhood of Darkness remain unknown. Similarly, the fleet's composition during the Brotherhood's initial campaigns, such as the Battle of Korriban in 1006 BBY, is unclear.
However, by 1003 BBY, the Sith fleet could spearhead the conquest of Kashyyyk, securing a foothold in the Mid Rim. In 1002 BBY, they achieved victory in the First and Second Battles of Ruusan, eliminating the Republic's staging area for counterattacks against Kashyyyk.
Around this period, the Sith fleet likely engaged in battles at Bespin and Sullust in the Outer Rim, followed by Taanab, near the Hapes Star Cluster. Kaan expressed surprise at the absence of a fleet led by Lord Hoth, the esteemed Jedi Master and General considered the Republic's foremost defender. The Jedi's disappearance from the war was sudden.
The clash at Taanab, situated along the Perlemian Trade Route in the Inner Rim, may have signaled the fleet's advance into the Core. Undeterred by the Jedi's apparent withdrawal, the fleet launched a campaign in Bormea sector, conquering Corulag, Chandrila, and Brentaal IV, and seizing control of both the Perlemian hyperlane and the Hydian Way from the Republic.
However, Lord Hoth then revealed his strategy. He had assembled the Jedi into a military force known as the Army of Light, and they liberated Ruusan. They defeated the defending naval squadron through a massive starfighter assault, compelling Kaan to return and confront them.
By 1000 BBY, during the final stages of the Ruusan campaign, most of the Sith fleet had been redeployed to protect Ruusan itself. They were entrenched in orbit, outnumbering the Jedi fleet in the outer system to prevent reinforcements from reaching the Army of Light.
During the Seventh Battle of Ruusan, Darth Bane, as part of his scheme to eliminate Kaan and the Brotherhood, instructed Admiral Nyras to abandon her defensive posture and engage the Jedi fleet. This allowed Lord Valenthyne Farfalla's gunships to penetrate the defenses and deliver reinforcements to the surface.
The Sith suffered defeat in that battle, resulting in the annihilation of Kaan and his Brotherhood.