The Great Houses began as various departments within the Imperial Bureaucracy. During the Isolation, they slowly seized control, absorbing other departments, consolidating power; eventually cementing themselves into positions of great authority within the city.

Each of the Great Houses controls a District of Rastaban, renamed in their honour.

• Great House Esteban used to be the Department of Taxation.
• Now they are Rastaban's largest banking conglomerate.
• Esteban headquarters is a large enclave pressed up against the walls of the Imperial Palace.

• Great House Telemere used to be the Department of Justice.
• Now they control the largest private army in the city, and their District boasts a formidable legal system.
• Rom Headquarters is a small fortress standing alone in a large expanse in their District.

• Great House Rom used to be the Department of Eduction and Extraplanar Affairs,
• Now they are a noble house comprised primarily of Plane Weavers.
• Their headquarters is on the grand boulevard built upon the blackened ruins of the national archive.

• Great House Keelen is not a Great House.
• The moniker is a joke, but reveals a deeper truth: Keelen wield enough power in Rastaban to rival the official Houses.
• Keelen are a collection of criminals, kingpins, and ne'er-do wells.
• Keelen provide smuggling, assassination and other services vital to the smooth running of legitimate business.
• Their base of operations is almost certainly somewhere in the Barrens, the District they claim as their own.