Onderon was a planet in the Inner Rim. Originally part of the Organian Empire, it later became one of the founding worlds of the Galactic Republic. The capital city of Iziz was also the site of the assassination of Conrad Bac and the Onderon Civil War. Leaders that were recognized by historians as being noteworthy were Talia Kira, Arael Maans and Kor Linth III. Adena Qel-Droma, Ussej Padric Bac and Kavari Antrell each served as Jedi Watchmen of the planet before, during and after the Great Territorial War, respectively.
The planet had four moons. Dxun was the primary moon and it orbited close to the planet, allowing some animals to fly between the planet and the moon. The other three moons were Dagari, Evas and Suthre. The native Humans of the planet struggled against the beasts, eventually gathering new technologies and building a huge wall around Iziz.