The Rakata were a civilization of total jerks from Lehon that used the Force to enslave the other species, including humans. They were in charge of what they stupidly called the Infinite Empire. Eventually, they basically destroyed themselves, and humans could take over the galaxy, much to the chagrin of the Duros. A few thousand years before that Yavin thing, the Rakata became extinct. The reason for extinction is widely believed to have something to do with the Rakata devotion to reality TV shows.