Byrsym was close to its system's sun, making it very hot during the day. During the night, when it was cooler, its population became more active. Byrsym had only one major spaceport, which catered for merchants and travelers. It was home to quite a lot of criminals.
Byrsym came under the control of the Galactic Empire, shortly after its formation. Following the Imperial occupation, Prince Torrin of the Royal House of Daimar established a rebel cell on Byrsym that opposed the Empire. After the Empire blockaded the planet Daimar, Torrin's father, King Mitar, sent some of Daimar's important figures to travel to Byrsysm and make contact with Torrin there.
- Flames of Rebellion (First appearance)