Some ten years before the onslaught of the Clone Wars, a group of would-be usurpers became discontent with Halcyon's membership in the Galactic Republic, and they captured several members of their homeworld's planetary government. The Republic tried to negotiate with the usurpers, but to no avail. Eventually, the Republic Senate dispatched members of the Jedi Order to Halcyon, along with eighty members of the Republic's Judicial Department.
- Tarkin (First mentioned, simultaneous with Tarkin audiobook)
- Tarkin audiobook
- Star Wars: Galaxy's Edge (Mentioned only)