It was home to the technologically advanced, but peaceful, Savothians.
The Savothians were nearly driven to extinction by an alien invasion until the scientist Gorflack inadvertently brought Jay Garrick, the first Flash, to their world. He rallied the Savothians and led them to victory against their invaders. Garrick and his successors became heroes to the people of Savoth and were given a device which would allow them to return.
The alien invaders were driven into the swamps of Savoth, but occasionally still made attacks against the Savothians, including an attempted assassination of the second Flash, Barry Allen. When only one invader remained alive on Savoth, he took Gorflack hostage, but was foiled by Wally West and Bart Allen. The incident resulted in the invader being sent to his home dimension in a Speed Force-powered explosion. The explosion caused rapid evolutionary changes in the alien, and its descendants later led an attack on Keystone City for revenge against the Flashes.
Wally and his family spent a year on Savoth after his battle with Superboy-Prime. After a short time there, his twin children, Iris and Jai, began to experience rapid growth. The Savothians had technology which would control their budding powers, but their law prohibited the Flash from using it. However, Wally's wife Linda was able to appeal to them, eventually receiving and being trained in the use of the technology.