Sahndara was the primary of a planetary system. One of its planets, the inhabited Sahndara, was the homeworld for a warp-capable species. Before Sahndara went supernova in the 1st millennium BC, a group of thirty-eight refugees traveled to Earth where they settled during the time of Plato.
After the time of Plato passed, the settlers, who called themselves Platonians, moved on to another planet which they named Platonius. Here they continued to follow the teachings of Plato, but soon they discovered that they had developed psychokinetic powers, attributed to the planet's kironide-rich food. (TOS: "Plato's Stepchildren")