Sith Supreme was a title intended to be used as the so-called true derogation of the Dark Lord of the Sith. It was created after the apparent death of Darth Plagueis and the ascension of his apprentice Darth Sidious. However, Plagueis was not killed, but instead he disappeared. Knowing that there could only be one Dark Lord of the Sith, he created the title in the hopes that he would one day be the rule of the Sith again. He took an apprentice called Darth Morg, and knowing Sidious' power would grow quickly Plagueis did what he could to disrupt the plans of his former apprentice.