Rule and Destruction
The Infinite Empire, controlled by the species known as the Rakata, were a powerful empire that spanned much of the galaxy around the time of 30,000 BBY (Before the Battle of Yavin). They conquered such planets as Kashyyyk, Tatooine, and many others. They enslaved countless races across the galaxy, using them to build many temples and their advanced creations, such as what was possibly their greatest creation, the Star Forge. The Rakata were Force sensitives, and were capable of adapting the Force into their technology. They lasted for possibly thousands of years before their inevitable decimation. A plague spread throughout the Infinite Empire, targeting the Rakata. They retreated to their homeworld, Lehon. The plague mutated, severing the Rakata's connection to the Force.
There, the Rakata - now mostly powerless - were subjected to civil war and infighting between the Rakatan factions. The Infinite Empire, at this point, had been completely destroyed. The galaxy at large almost completely forgot them, traces of the Infinite Empire almost completely wiped from the archives.