The River Aumris is the primary river system of northwest Eärwa, draining the greater Istyuli Plains basin and emptying into the Neleöst Sea. The River Aumris is the cradle of Norsirai civilization. Over a relatively brief period of time, the High Norsirai tribes that settled the rich alluvial plains along the lower Aumris founded the first cities of Men, including Trysë, Sauglish, Etrith, Lokor, and Ûmerau. As the result of trade with the Nonmen of Injor-Niyas, the power and sophistication of the Aumris River civilization grew quickly, culminating in the Trysean Empire under the God-King Cûnwerishau in the fourth century.