History of the Sith
i found this on the force.net which i found quite interesting
i always wondered why there was only 2 sith at once
The book also gives a history of the Siths. And that the Siths wiped each other out and only one survived - Darth Bane. He developed the idea of only two Siths at a time to prevent internal problems. Lucas has said: "One of the themes throughout the films is that the Sith Lords, when they started out thousands of years ago, embraced the Dark Side. They were greedy and self-centered and they all wanted to take over, so they killed each other. Eventually there was only one left, and that one took on an apprentice. And for thousands of years, the master would teach the apprentice, the master would die, the apprentice would then teach another apprentice, become the master, and so on. But there could never be more than two of them, because if there were, they woud try to get rid of the leader, which is exactly what Vader was trying to do, and that's exactly what the Emperor was trying to do. The Emperor was trying to get rid of Vader, and Vader was trying to get rid of the Emperor. And that is the antithesis of a symbiotic relationship, in which, if you do that, you become cancer, and you eventually kill the host, and everything dies." So does this mean there CAN be more Sith than two? Cool.