Vintage Star Wars
Tython was a planet located within the Tython system of the Deep Core. It was the planet where the Jedi Order originated, in the form of the first society of Force users in known history, sometime between 36,453 BBY and 25,990 BBY.
It was on this world that the brightest and best philosophers, priests, scientists and warriors came together in 36,453 BBY to discuss their discoveries involving the enigmatic, mystical Ashla. Dissidents who used the Bogan eventually arose around 25,793 BBY, sparking the Force Wars of Tython. From the ashes of these wars arose the early Jedi, whose Jedi Forge initiation ceremony led to the invention of lightsabers after they faced threats from beyond Tython.
Initially, the Jedi believed their power was limited to Tython only, though this was later proven otherwise when a proactive group left Tython to liberate other worlds, becoming the Jedi Knights around 25,783 BBY. Jedi from Tython founded a philosophy school on Ossus, defining the light side and dark side of the Force (equivalent, respectively, to the ancient Ashla and Bogan), and the Living Force and Unifying Force. Some legends claimed that Tython’s explorers traveled to Caamas to learn proper moral judgment.
Old Republic era
Tython was cleansed of terentateks by the Great Hunt in 3,994 BBY.
In the aftermath of the Great Galactic War, the Jedi Order relocated to Tython following the Sacking of Coruscant in 3,653 BBY. There, they attempted to rebuild their order and the Jedi Temple on Tython was rebuilt after the Treaty of Coruscant.
~ all according to wookieepedia, the Star Wars Wiki