The Realms
Following the Great Upheaval of 704, the three Kingdoms that had occupied the Sister Islands were relocated onto the main (and sole surviving) island of Gerydon, and Gerydon was divided into the Realms.
Ptah City
The City of Ptah is not exactly a Realm, but not exactly not a Realm either. It is the seat of the High Queen Edain, from which she rules the Sederan Empire. While parcelling out the rest of Gerydon Island, the High Queen kept the City of Ptah (and the lands directly east of it) for her own use.
Auxesia
The Realm of Auxesia is located furthest south, and encompassed all the land south of the Brodhidya River and east of the Firerun River.
It is ruled by Queen Caire of the Rarehart Clan.
Cletia
The Realm of Cletia is located in the middle-eastern part of the map, bounded by the Eyara and Brodhidya Rivers to the north and south, and the Firerun River to the west.
It is ruled by King Mattan of the Bloodmoon Clan.
Phaenna
The Realm of Phaenna is located on the northern tip of the island, bounded by the Eyara River to the south and the Firerun River to the east. While it is not wealthy in gemstones like the Auxesia Island, a seam of coal has been discovered in the Fireheart Mountains that fall within the Realm.