Being that I had promised a part two, here it is. This is a bit later in SW history. Hope you enjoy!

Marka Ragnos~ Known as the greatest Dark Lord of the ancient Sith Empire, reigning for a century. Marka Ragnos was... wow, actually it doesn't say much about him. Sorry.

Naga Sadow~ One of the most influential Sith Lords in history, Naga Sadow was infamous for enslaving and distorting his followers of the Massassi species into hideous savages, corrupted by the forces of the Dark Side. The Massassi were unbelievebly loyal to Sadow, raising up great temples in his honor, despite Naga's cruel experiments done on them. Sadow was also well known for his passionate rivalry with another dark lord, Ludo Kressh, having various conflicts with his opposing Sith while debating over a matter of superiority and qualification for the coveted title of Dark Lord of the Sith. Proving superior to Ludo, Sadow finally recieved his title as the new dark lord.
On yet another famous occasion, Naga assaulted the Republic in his ship, Starbreaker 12, accompanied by a fleet of loyal followers, but failed in the attempt.
Sadow died when his apprentice, Freedon Nadd murdered him, taking his title of Dark Lord of the Sith.

Exar Kun~ A talented Jedi Apprentice, Exar Kun turned to the Dark Side of the Force in an unfortunate turn of events involving the sinister Freedon Nadd, he took on the title of Dark Lord of the Sith. On a voyage to Yavin IV, he encountered the remnants of Naga Sadow's Massassi warriors. Kun soon took control of them as did Naga, the savages lifting him up as a god, and building the Great Temple that the Rebel Alliance later would make their base.
Later on in his life, Kun took on an apprentice, Ulic Qel-Droma.
Following a deadly duel with Odan Urr and Vodo-Siosk Baas, his former master, Kun preceeded to an attack on the Galactic Senate.
His apprentice turned on him, betraying his whereabouts to the Republic. Still, he fought, but failed, becoming a spirit for many years to come.

That's all for now!!! Actually, I may make a Part III...

May the Force be with you!!!
God bless!!!