This quadrumvirate has been birthed from the distillation of the Empire's most skilled and hardened devotees. That purity will be a blade into the heart of the Galactic Republic.
—Darth Hamon, to his fellow founders.
The Sith Quadrumvirate, often referred to simply as the Quadrumvirate or the Empire, was the successor state of Vitiate's Sith Empire after its collapse at the end of the third Galactic War. It was founded by Darth Hamon, who gathered several of the most prominent Sith remnants together to reorganize the Sith Empire and launch a new campaign against the Galactic Republic, beginning the fourth Galactic War.