The Sith Empire
An ancient order of Force-wielders devoted to the dark side, the Sith practiced hate, deception, and greed. Notable for their red-bladed lightsabers, black dress, and use of their aggressive feelings, the Sith looked to amass power at all costs.
Power tends to attract those seeking power, just as fear attracts the fearful. At the height of its power, the Sith Empire had as many planets and citizens as the Republic, and the two constantly vied for control of the galaxy.
The Sith Empire was finally defeated over a thousand years ago through the combined might of the Old Republic military and the Jedi Order, though at heavy cost to both. In the aftermath, the remains of the Jedi Order and the Republic Senate united to form the new Galactic Republic.