Erzerum is a mountainous region that lies between the inland Mylasa Sea and the Videssian Sea and is bordered to the north by Pardraya and by Makuran to the southwest and Vaspurakan and the Empire of Videssos to the southeast.
Erzerum is divided into numerous valleys occupied by many peoples of different faiths, religions, sects, and languages. Makuran and Videssos realized that it was in their joint interest to prevent the Khamorth from swarming south through Erzerum and into their empires. The two states collaborated to build a fortress in northern Erzerum called Gunib which prevented the Khamorth from entering Erzerum.
Known peoples inhabiting Erzerum include the Yrmido, the Redzh, Mzeshi, the Shnorhali, the Gunibi, and the Khakuli. Many of the peoples inhabiting the region are persecuted exiles. Some were driven off the Pardrayan steppes by other clans, or fled from religious persecution in neighbouring countries. Not all left behind feuds and sometimes pursued open warfare with other Erzrumi tribes.
All the known Erzrumi tribes mentioned above fought against the Yezda and were part of the Arshaum host that invaded Yezd. However, because the defenders singled them out for fighting, most left the host and returned to their homes except for the Yrmido and some other tribes.