One of the larger duchies in south-central Dragaera.
It was named for the leader of the settlement expedition, a Dzurlord named Arylle, and is located to the north of the Duchy of Luatha, and directly to the east of the Collier Hills, alongside the Yendi River.
It consists of eleven separate counties of excellent farmland, which include Groomsman, Pitroad, and Bra-Moor, which is the capital. Originally thought to be a useless marshland, the area proved to be a fertile region excellent for growing wheat, maize, and various types of legumes.
Founded as a county, the area was raised to a duchy during the ninth Vallista reign, as a favor to Corpet's daughter, who aided the Emperor in a conflict with certain rebellious factions within the Empire.
It is unclear who inherited rule of the duchy after the death of Aerich in the events surrounding the Battle of Adrilankha. He had no descendants, and no living relatives that we are aware of.
The county of Bra-Moor contains at least one barony that we know of; Daavya.