The Sith military was the armed forces of the Sith Empire during the Jedi Civil War and the Sith Triumvirate during the Dark Wars and First Jedi Purge.
The Sith military's roots began in the Mandalorian Wars, with the Jedi Knight Revan appointed Supreme Commander and granted direct command of a third of the Republic Military. Towards the end of the Mandalorian Wars, Revan began to fall to the dark side of the Force. At the climatic Battle of Malachor V, Revan used the Mass Shadow Generator to destroy the Mandalorian fleet. This also solidified his control over his forces, as many of the Republic casualties were among forces not directly loyal to him. Following the end of the war, Revan's Republic forces followed him into the Unknown Regions. Officially this campaign was directed at elminating Mandalorian Neo-Crusader remnant, however the actual purpose was to seek out the Sith Empire, which had secretly reformed after the Great Hyperspace War and orchestrated the Mandalorian Wars.
Following Revan and Malak's fall to the dark side at the hands of the Sith Emperor, the pair were tasked to locate the Star Forge however, they broke free and established their own Sith Empire and organized their Republic forces as the Sith military.
Military movement in the Jedi Civil War.
Reconstituted by the near-limitless production capability of the Star Forge, the Sith military had the manpower and personnel to mount a full scale assault on the Galactic Republic. The opening battle of the Jedi Civil War was the Battle of Foerost in 3959 BBY, during which the Sith military captured a significant portion of the Republic Navy's fleet at the Foerost Shipyards. Significant segments of the Republic Military defected to the Sith military, enabling rapid advances with minimal casualties. Logistics support and materiel was provided by agreement with the Czerka Corporation.
During 3958 BBY, Republic Navy Admiral Saul Karath defected to the Sith Empire. One of his first acts as a Sith admiral was to lead the Bombing of Telos IV. The orbital bombardment was unprecedented in its scale, killing millions and served to send a message to the Republic on how far the Sith were willing to go. In 3957 BBY, Darth Revan was captured by the Jedi, however Darth Malak attempted to kill his former master and sized leadership of the Sith Empire and its military.
Following Malak's assumption of leadership, the military campaign shifted from strategic conquest, with an emphasis on preserving industrial capacity, to one of total war. In 3956 BBY the Sith military captured Taris and launched an attack on the Republic Hammerhead-class cruiser Endar Spire in an attempt to neutralize Bastila Shan. Following Shan's rescue by Revan, who had his brain wiped and was now working for the Republic, Darth Malak directed the destruction of Taris which killed billions of citizens and shocked the galaxy.
Sith forces engaged with Revan during his quest for the Star Maps during his raid on the Manaan Sith Embassy. At Darth Malak's direction, the Sith military launched an attack on Dantooine, executing orbital bombardment and surface operations, destroying the Jedi Enclave and occupying the planet. Sith forces also briefly captured Revan before he escaped after killing Admiral Karath aboard the Interdictor-class cruiser Leviathan. Revan proceeded to eliminate the Sith Academy on Korriban while finding the last Star Map. The Battle of Rakata Prime marked the end of the war, with the death of Darth Malak, the destruction of the Star Force, and fracturing of the Sith Empire and its military. General uprisings occurred, such as the Ahto Uprising, as worlds revolted against Sith rule.
While the Sith Empire had fractured and various Sith lords and military commanders fought for power as their influence crumbled, elements eventually coalesced into the Sith Triumvirate led by Darth Traya, Darth Nihilus, and Darth Sion. While they did not have the outward power that Revan did, either in troops or materiel, the Sith Triumvirate instead opted for covert action by Sith assassins to execute the First Jedi Purge.
During the Conclave at Katarr Darth Nihilus wiped out life across the entire planet and killed many members of Jedi Council. Sith forces under Darth Sion pursued the Jedi Exile Meetra Surik to Peragus II, destroying the vitally critical source of fuel for Citadel Station at Telos IV. Sith forces under Darth Nihilus also intervened in the Onderon Civil War on behalf of the Onderon separatists, first covertly, then overtly during the Second Battle of Onderon. Darth Nihilus then assaulted Telos IV with the remainder of his space and ground forces, before being killed by Surik. The Sith Triumvirate and Sith military were finally defeated in the Battle of Malachor, with the death of Darth Traya and Darth Sion marking the end of the Dark Wars and First Jedi Purge in 3951 BBY.
The military's soldiers were called commonly called Sith troopers and wore silver armor and helmets completely hiding their natural bodies.
Many of the Sith military's officers and enlisted personnel were former members of the Republic Army and Republic Navy who defected prior to, or during the start of, the Jedi Civil War. Notable senior officers include Admiral Saul Karath, who led the Sith military's space forces after his predecessor was removed for questioning the orders of Darth Malak, Admiral Varko, who succeeded Admiral Karath, and General Derred.