Naga Sadow
In the days before our great emperor came to power the Dark Lord of the Sith Marka Ragnos ruled the Sith people. When he died Ludo Kresh was to be the new Dark Lord, but the Sith warleader Naga Sadow opposed him and wished to become the Dark Lord of the Sith. During the ensuing duel the ghost of Marka Ragnos appeared to them and commanded them to stop fighting, so began a great war that ended in the defeat of Ludo Kresh. In a way it would have been better if Naga Sadow had lost the war instead, because when two human children strong in the force came upon our home world of Koraband. Interested in where they had come from. When he learned about the Repuplic he instantly prepared the entire Sith Empire for war. He allowed the girl to leave but kept the boy to teach him the arts of the dark side. The girl returned to the Republic and warned them of the invasion. Naha Sadow's army tracked her to the Republic where they proceeded with the invasion. A Jedi scholar by the name of Odan Urr devised a plan to counter our attack: Jedi battle meditation. They used force telepathy to create fear in the minds of our men and courage into theirs.
In short Naga Sadow was defeated and fled to the remote world of Yavin IV where he tried, without success, to return his empire to its former glory.
Okay so who will be next tell me in the comments if you have any requests.