They were once a single nation, the Kingdom of Urnst, a "mildly tyrannical" dominion named after a royal house of the ancient Suel. The County of Urnst was established as a distinct protectorate nation in 189 CY by Overking Jirenen of Aerdy. It was captured by Nyrond after that nation broke from the Great Kingdom, and as a result has greater Oeridian influence than the Duchy, although both are independent of Nyrond today.
- Gygax, Gary. The World of Greyhawk. Lake Geneva, WI: TSR, 1980.
- -----. World of Greyhawk Fantasy Game Setting. Lake Geneva, WI: TSR, 1983.
- Holian, Gary, Erik Mona, Sean K. Reynolds, and Frederick Weining. Living Greyhawk Gazetteer. Renton, WA: Wizards of the Coast, 2000.