The Republic Dark Age data created by Wikia user Lukewarner.
See also: Eras of Play
In 1,100 BBY The Old Republic collapsed. Centuries of fighting The Sith had drained the economies of countless worlds, and conscription had dipped to critical levels as able-bodied adults became a scarce commodity. The government of Coruscant could no longer afford to maintain The HoloNet communications network and left the Rim in the dark with only courier ships to carry messages. Finally, an outbreak of the Candorian plague killed as many as two-thirds of the inhabitants of Republic worlds.
The Sith saw the developments as a sign that The Force was with them. With the promise of Coruscant just ahead, their ranks fell apart over who would rule the unified Sith galaxy.
Timeline 
Edit
The Republic Dark Age is an infamous century in Star Wars lore. The Old Republic is scattered, and The Sith are largely unopposed in their conquest of the galaxy. The following list is of major conflicts and events of this time.
The First Charge Matrica (1,066-1,050 BBY) Edit
A contest among the seven children of Vilia Calimondra to determine the next ruler of the Calimondra Empire. While initially tasked with expanding the Empire, Vilia's Sith children soon came to war against one another. During this Civil War, Sith expansion is largely halted, giving allowing the greater galaxy a small reprieve.
Initial conflict began when Xelian, an ambitious daughter known as "The Destroyer," declared war on Chagras, the shrewd son who had already expanded his mother's Empire. Soon, the remaining six siblings were drawn into conflict, beginning a Civil War.
The first Charge Matrica would eventually end with Chagras' victory, and he would go on to reorganize the Calimondra Empire into his own Chagras Hegemony. Soon after, Sith conquests of Republic Space resumed in force.
The Second Charge Matrica (1,040-1,032 BBY) Edit
Operation Influx (1,032 BBY) Edit
The Light and Darkness War (1,010-1,000 BBY) Edit
In 1,010 BBY Lord Kaan's faction, the Brotherhood of Darkness, emerged victorious. Kaan made his headquarters on Room, and within a few years the Brotherhood had retaken Korriban and established a new Sith training academy to provide fodder to throw against the Republic war machine. Other worlds selected for training included low-level outposts on Honoghr, Gentes, and Gamorr; spy schools on Ryloth, Umbara, and Nar Shaddaa; and advanced facilities on Dathomir and Iridonia to groom the next generations of Sith Lords.
Kaan's war began in earnest in 1,004 BBY. The Brotherhood of Darkness landed occupying armies on Dromund Kaas and Malrev IV, only to be repulsed from each by furious Republic counterattacks. Kaan regrouped and launched a second wave, rolling over the Wookiee homeworld of Kashyyyk and chasing the retreating Jedi to neighboring Trandosha. In the Trandoshan city of Hsskhor, the Brotherhood of Darkness annihilated The Jedi holdouts and any natives bold enough to challenge them, buying the allegiance of the surviving Trandoshans in conflicts to come.
After Trandosha, The Sith racked up a grim string of victories. The Brotherhood's elite Gloom Walkers subjugated Phaseera, while Dark Side marauder Kaox Krul wiped out the Duros colony of Harpori. As Kaan grew in certainty that he would soon rule the galaxy, he attacked Ambria, Taanab, and the galactic southern quadrant at Bespin and Sullust, baiting the ranking Jedi commander, Lord Hoth, into meeting him in a winner-take-all showdown.
In 1,001 BBY Lord Hoth's Army of Light finally crossed blades with Lord Kaan's Brotherhood of Darkness at Ruusan. The obscure world had been used by the Republic fleet as a staging area to harass The Sith stronghold at Kashyyyk, and the Republic crumpled under the onslaught. A counterattack to recapture the planet failed, and an overconfident Kaan decided the time had come for a strike at The Core. His legions descended on the Bormea Sector, launching coordinated strikes on Corulag, Chandrila, and Brentaal in an effort to choke off the Hydian Way and the Perlemian Trade Route. But Kaan miscalculated- with his forces elsewhere, Lord Hoth arrived at Ruusan to smash The Sith blockade and land an occupation army. The two ideological opposites fought bitterly over every centimeter of land, with Ruusan's peaceful natives left to watch their homeworld's slow death.
The Army of Light received reinforcements from Lord Farfalla, who had smashed the navy of formed Jedi King Lahzar in the Tholatin System. The Sith, however, amassed their mental energy and released a Force shock wave that defoliated the planet. Lord Hoth had had enough, and in the Seventh and final Battle of Ruusan he confronted a deranged Kaan inside a dark and cold cavern. With a clap of his hands, Kaan detonated a Thought Bomb that pulled the spirits of the Jedi and Sith combatants into an incorporeal vacuum, centered on what would become known as the Valley of the Jedi.
A single Sith Lord, Darth Bane, escaped to establish a new Sith Order under the precept of the "Rule of Two." The Republic, meanwhile, realized it had narrowly escaped extinction. Supreme Chancellor Tarsus Valorum seized the occasion to announce the Ruusan Reformations, which rebuilt the Republic government from the ground up.
