The title of the head of the church is "Nali", the references indicate it was based in Aventin, somewhere on Aerlinthe and part of the Haebrous lands.
In HE 142 Nali Athanas reforms the Northern Church.[1]
After Emperor Kellin II converts to the Northern Church, the Nali spreads the word of the Northern Church throughout the Empire and the ranks of followers grow.[2] In HE 239 the Nali relocates from Aventin to Tentael at his invitation.[3]