The Massassi were one of three species, which lived in the underground caverns of the planet Korriban. The others were the Original Sith and the Korribanites. These Massassi were the descendants of the originals, who were created by Sith alchemy during the Great Hyperspace War. Their leader at the year 27 ABY, was named simply The One. He was called such, because he was the one and only leader the Massassi could have. It is rumored that he was force-sensitive. The Massassi were part of the allied attack on the Court of Yun-Coria.