Preffilo is a city on Home. In ancient history it was a stronghold of the Ssumaz dynasty; after the Race was unified under that dynasty, it became the Empire's capital. It is one of the few places on Home where the Race's ancient history is clearly in evidence after the planet's 100,000 years of political unity. The city's grand ancient buildings include the Emperor's palace and a shrine to the Spirits of Emperors Past which houses those emperors' physical remains.

Persons granted audiences with the Emperor are given free transport to Preffilo from anywhere on Home at the government's expense.